When you say deploy, you mean the forge deploy command?
One thing that I had in the past was that I’ve used my wrong Atlassian account.
An app that is deployed to the Marketplace is associated with a single account (Jira Developer Account for multiple users - #2 by ibuchanan). As part of the initial deployment in the manifest.yml it stores a unique app id.
To deploy the the existing code to another Atlassian account there is a command to get a new app id for the other account. If I’m not wrong it was forge register command. Otherwise you won’t be able to deploy.
Maybe first check if you have logged in with the correct account forge whoami.