Publish the prepared AMI on AWS Marketplace

Hi,

We have prepared an AMI that fits our product. Now we are trying to publish it on AWS MP, however, we are always getting the below error:

Failed to launch instance or failed to reach port 22.

Everything is prepared correctly and the SSHD config is OK along with the private keys, etc. Is there any guide to make sure the AMI is OK for the marketplace, or anyone knows what is missing in or wrong with our AMI, or what could be missing with our subscription?

Regards,

Erturk V.