how to use powershells sharepoint PnP module change columns conditional formulas?

childishbambino You can use PnP PowerShell code like below to apply conditional formula to list fields: 

$conditionalFormula = "=if[{0}],'true','false')" -f '$myColumnB'
 
# Get SP list field
$field = Get-PnPField -List "Tasks" -Identity "ColumnA"
 
# Apply conditional formula to column
$field.ClientValidationFormula = $conditionalFormula
$field.Update()
Invoke-PnPQuery

Where ColumnA is the internal name of your SharePoint column. You can get the internal name of column using various methods shown in this article: How to find the Internal name of columns in SharePoint Online? 

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