Zapier api code not valid in V5

Migrated to V5. When I try to make a Zapier connection I get the message:
Authentication failed, your api key isn’t valid

Is there a problem with V5 and Zapier or should something be different then with V4?

Just read another reply where there seems to be an version 5 of Zapier (connection to Invoice Ninja). So I recreated the Zap and searched for Invoice Ninja - V5 app in Zapier. Now it works.