This is not how publishing games works.

A publisher signs titles that they believe in, and they cover “publishing duties.” In exchange, pays the developer. It could be an up front payment, it could be a percentage of sales, it’s often a mix of both.

Publishing duties involve, at the very least, “publishing” the game on platforms. Managing the relationships with Sony, Steam, Microsoft, Nintendo, Epic, Apple, Google, whatever, and listing the game. They’re often responsible for all marketing duties (often including social media and community management, but not always), PR, developing key art (aka box art) and a game logo, a website, etc etc etc.

The goal of a publisher is to join forces with a smaller dev team without those resources or expertise, so the developer can just focus on the game and the publisher handles everything beyond that.

Source: Have worked on both the publishing and indie dev side.