Maybe this is helpful:
https://github.com/rgl/azure-content/blob/master/articles/virtual-machines/virtual-machines-linux-add-user.md
https://msicc.net/create-an-additional-ssh-login-enabled-user-for-your-azure-linux-vm-without-third-party-tools/
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Andreas Baumgarten