Hello @Symira
Is the String Maps entity created in that Environment/Organization?
To check if the entity exists. Click the Data tab in Power automate. This will bring you to Power Apps page. Check inside the data tab for the String Maps entity.
If the entity is in fact created and showing in Dynamics / CDS..
Check your connection settings. As the connection may not have access to that entity.
—Josh
If you like my post please hit the "Thumbs Up" -- If my post solved your issue please "Mark as a Solution" to help others