Web API: How to retrieve a record based on an alternate key with lookup field?

Hi

Using Web API, we are used to retrieve a record quite often with an alternate key:

{{webapiurl}}/cr23b_tmps(cr23b_string1='abc')

However, in this case, the alternate key is based on a lookup (e.g. accountid). Adding a lookup field in an alternate key should be possible, according to this documentation: https://docs.microsoft.com/en-us/powerapps/developer/common-data-service/define-alternate-keys-entity

In Web API, I don't seem to find a right way to use the alternate key (based on lookup) in a GET request. These are some tests which did not work:

• GET {{webapiurl}}/cr23b_tmps(cr23b_accountid=’1275227F-93A8-E911-A821-000D3ABA5555')
• GET {{webapiurl}}/cr23b_tmps(cr23b_accountid='/accounts(1275227F-93A8-E911-A821-000D3ABA5555)')

Does anyone know how to do this?

Kind regards.