Today I ran into the following error, after I found the following request on the Flow community site.

BadRequest. The request failed. Error code: 'InvalidApprovalSubscribeRequestAssignedToMissing'. Error Message: 'Required field 'assignedTo' is missing, empty, or contained no valid users.'.
It just sounds like I’ve typed the user account incorrectly in my Start an Approval action but I have not.
Then I replaced the account with a different Office 365 account and all worked fine.
Hmm, what is missing? My Trial environment definitely had a user account created for meganb!

Or did it? I checked all my users and there is no meganb. Hmm, not sure why these demo environment give me these accounts that don’t really exist.
Then I thought about external users.

And As expected I got the same error again

My conclusion is to avoid this error you will have needed to add the user ( internal or external) to your environment either as a user or as an external user.
We have two companies i.e. mycompany.com and mycompany.ae.mycompany.com has an O365 E3 license but mycompany.ae doesn’t have an O365 license. We create MSFLOW ( Power Automate ) with approvals. the users of mycompany.com (Requestor) can use the approvals (to send approval to their managers) ALL managers have an O365 E3 license (.com)but
the users of mycompany.ae (Requestor) cannot use the approvals (to send approval to their managers)
ALL managers have an O365 E3 license (.com)We found this article that resolve this issue. So we create the O365 group and add mycompany.ae users in that group as guests. Now question is that we don’t know the Microsoft legal issue, are we allow to use it like that or do we required the license for those users.
we will get into a “grey area” with compliance against Microsoft Licensing.
The reason what we think:
We own the domain (mycompany.ae);
These are all employees of mycompany.ae;
mycompany.ae employees require access to mycompany.com resources e.g.( O365 group as a guest) they are not licensed for.
Hi Muhammad,
I would probably ask Microsoft support that question.
For some features if you have a licence within your home tenant then you could use that same features in other tenants as a guest without running into licence issues.