Inbound fax-to-email recipient

Hey people. I created a virtual extension and gave it an email address. Then I added an inbound route and chose “Fax Recipient” and picked the virtual extension. Whenever I call in, it rings once or twice and I get the “You have reached an invalid number” recording and the below appears in the log. What can I look for that would be causing this?

pbx.c: Channel ‘SIP/flowroute-00000015’ sent into invalid extension ‘5000’ in context ‘ext-fax’, but no invalid handler

Did you call it from a fax machine?

not call fax from fax machine.