Approval flow between 2 tenants

[MyInventedUser]

We have a scenario where users from tenant1 are asking for approval guest users from tenant2.

The flow works up to a point where tenant2 user receives an email with the options to approve and reject.

The tenant2 user clicks on SUBMIT and receives an error "The remote endpoint returned an error (HTTP Forbidden). Please try again later."

Nothing shows up in the Flow logs on Tenant1 or during the flow testing.

What endpoint is being called in this scenario and what permissions should we assign to tenant2 users on tenant1 resources?

[v-yamao-msft]

Hi @MyInventedUser,

So the requester and approver are in a different tenant?

If yes, I am afraid that the approver might be not able to give a response cause he/she doesn’t have an access to tenant1.

Please check this doc for a reference:

https://docs.microsoft.com/en-us/flow/organization-q-and-a

Best regards,

Mabel Mao

[MyInventedUser]

To what exactly are they missing access?

They have full control over the site collection where the workflow is triggered.

I didn't find anything related in the link provided other than general Flow information.

[LucasKo]

I have the same issue.

I registered the external user as a B2B user (guest) and assigned Flow for Office 365.

Can we just know whether it is supported or not? 

[Cantrell]

Having the same issue; cannot find a fix