Remove permissions from library and add users sharepoint online

Hello, below powershell script is to create multiple libraries and then remove existing permissions and then adding a new user permissions. Its creating document libraries in sharepoint online but fails to remove existing permissions and add new user permissions. Please help

#Load SharePoint CSOM Assemblies
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.dll"
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.Runtime.dll"

$UserName=""
$Password =""

$AdminURL = ""     
$UserID = "email address removed for privacy reasons"
Connect-PnPOnline -Url $AdminURL -Credential $Cred
  

#Function to Create a SharePoint Online document library
Function CreateSPO-DocumentLibrary()
{
[cmdletbinding()]
    param
    (
        [Parameter(Mandatory=$True,ValueFromPipeline)] [String] $LibraryName,
        [Parameter(Mandatory=$False)] [String] $Description,
        [Parameter(Mandatory=$False)] [Switch] $ShowOnQuickLaunch
    )   
    Try {
            Write-host -f Yellow "`nEnsuring Document Library '$LibraryName'"
         
            #Get All Existing Lists from the web
            $Lists = $Web.Lists
            $Ctx.Load($Lists)
            $Ctx.ExecuteQuery()
 
        
            #Check if Library name doesn't exist already
            If(!($Lists.Title -contains $LibraryName))
            {
                #Set Quick Launch Option
                If($ShowOnQuickLaunch.IsPresent)
                {
                    $QuickLaunchOption = [Microsoft.SharePoint.Client.QuickLaunchOptions]::On
                }
                Else
                {
                    $QuickLaunchOption = [Microsoft.SharePoint.Client.QuickLaunchOptions]::Off
                }
 
                #Create Document Library
                $ListInfo = New-Object Microsoft.SharePoint.Client.ListCreationInformation
                $ListInfo.Title = $LibraryName
                $ListInfo.Description =  $Description
                $ListInfo.TemplateType =  [Microsoft.SharePoint.Client.ListTemplateType]::DocumentLibrary
                $List = $Web.Lists.Add($ListInfo)
                $List.OnQuickLaunch = $QuickLaunchOption               
               
               #Set-PnPList -Identity $LibraryName -BreakRoleInheritance
               
               $List.BreakRoleInheritance($true, $false)
               Set-PnPListPermission -Identity $LibraryName -AddRole "Edit" -User $UserID

                #Set-PnPList -Identity $ListInfo.Title -BreakRoleInheritance -ClearSubscopes 
                # Set-PnPList -Identity $LibraryName -EnableVersioning $True -EnableMinorVersions $True -CopyRoleAssignments:$False -BreakRoleInheritance:$True -ListExperience NewExperience
               

                # load the list role assignments
                #$Ctx.Load($listName.RoleAssignments)
                #$Ctx.ExecuteQuery()

                # remove the visitor group from the list
                #$listName.RoleAssignments.Groups.Remove($Group)
                #$Ctx.ExecuteQuery()                         
            $RoleAssignmentCount = $List.RoleAssignments.Count 
            #Remove All Permissions from the List
            For ($i= $RoleAssignmentCount-1; $i -ge 0; $i--)
            {
                Write-host "Removing Permission from:"$List.RoleAssignments[$i].Member.name
                $List.RoleAssignments.Remove($i)
            }

            

                $List.Update()
                $Ctx.ExecuteQuery()
  
                write-host  -f Green "`tNew Document Library '$LibraryName' has been created!"
            }
            Else
            {
                Write-Host -f Magenta "`tA Document Library '$LibraryName' Already exists!"
            }
    }
    Catch {
        write-host -f Red "`tError:" $_.Exception.Message
    }
}
 
#Set Parameters
$CSVFilePath = "C:\Folder\DocumentLibs.csv"
 
#Get Credentials to connect
#$Cred = Get-Credential

$Cred = New-Object -TypeName System.Management.Automation.PSCredential -argumentlist $UserName, $(convertto-securestring $Password -asplaintext -force)
Connect-SPOService -Url $AdminURL -Credential $Cred  
 
#Get the CSV file
$CSVFile = Import-Csv $CSVFilePath
 
#Read CSV file and create a document library
ForEach($Line in $CSVFile)
{
    #Setup the context
    $Ctx = New-Object Microsoft.SharePoint.Client.ClientContext($Line.SiteURL)
    $Ctx.Credentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($Cred.Username, $Cred.Password)
   
    #Get the web from URL
    $Web = $Ctx.web
    $Ctx.Load($Web)
    $Ctx.executeQuery()
     
    #Get the ShowOnQuickLaunch option
    $ShowOnQuickLaunch = [System.Convert]::ToBoolean($Line.ShowOnQuickLaunch)
 
    #Call the function to create document library
    If($ShowOnQuickLaunch -eq $True)
    {
        CreateSPO-DocumentLibrary -LibraryName $Line.LibraryName -Description $Line.Description -ShowOnQuickLaunch
    }
    Else
    {
        CreateSPO-DocumentLibrary -LibraryName $Line.LibraryName -Description $Line.Description
    }
}