Calendar sharing

Hello.

Cannot find any decision for resolving issue with sharing calendar between two organization. Both are using exchange on-prem.

Has anyone found the solution, please?

Testing with test-organizationrelationship return error like :

VERBOSE: [08:28:31.482 GMT] Test-OrganizationRelationship : Failed to get delegation token: <Lifetime
t:xmlns="http://schemas.xmlsoap.org/ws/2005/02/trust">
Microsoft.Exchange.Net.WSTrust.SoapXmlMalformedException: Soap message XML is malformed.
at Microsoft.Exchange.Net.WSTrust.SoapClient.GetRequiredChildElement(XmlElement xmlElement, XmlElementDefinition xmlElementDefinition)
at Microsoft.Exchange.Net.WSTrust.SecurityTokenService.ParseRequestSecurityTokenResponse(XmlElement requestedSecurityTokenResponseElement,
TokenTarget target)
at Microsoft.Exchange.Net.WSTrust.SecurityTokenService.IssueToken(DelegationTokenRequest request, XmlTextWriter debugStream)
at Microsoft.Exchange.Management.Sharing.TestOrganizationRelationship.GetDelegationToken().
RESULT: Error.

Identity :
Id : FailureToGetDelegationToken
Status : Error
Description : Failed to get delegation token: <Lifetime t:xmlns="http://schemas.xmlsoap.org/ws/2005/02/trust">
Microsoft.Exchange.Net.WSTrust.SoapXmlMalformedException: Soap message XML is malformed.
at Microsoft.Exchange.Net.WSTrust.SoapClient.GetRequiredChildElement(XmlElement xmlElement, XmlElementDefinition
xmlElementDefinition)
at Microsoft.Exchange.Net.WSTrust.SecurityTokenService.ParseRequestSecurityTokenResponse(XmlElement
requestedSecurityTokenResponseElement, TokenTarget target)
at Microsoft.Exchange.Net.WSTrust.SecurityTokenService.IssueToken(DelegationTokenRequest request, XmlTextWriter debugStream)
at Microsoft.Exchange.Management.Sharing.TestOrganizationRelationship.GetDelegationToken().
IsValid : True
ObjectState : New