Hi @Jack Wright ,
I understand that you would like to add PowerShell modules registered to 7.1 runtime via bicep.
Currently PowerShell 7.1 runtime is supported only through the Azure Portal. API changes for ARM / bicep and PowerShell cmdlets are not yet implemented. We are tracking this as part of PowerShell 7.1 GA. Tentative ETA is moved to Q4 CY22 as service is undergoing some of the major architecture level changes.