How to contribute money to the development of the project?

Well. I think, we now have enough votes on the importance of this issue.

How can we get ahead now?

I myself cannot do the coding, but I’m very well willing to give a little money. Hopefully, other fellows do as well. IMHO, there should be

  • a good description of the issue (could be extracted from this thread)
  • a collection of money
  • a call for offerings
  • coding
  • code review and introduction

AFAIK, we do not have any structure to do so, but I think we should. And I think there should be a reward for the work on code review. I would be ashamed to request all that for free.

Cheers,
Wolf

For now the only option is to hire a service provider to do the coding for you or to do the coding by yourself. In case of hiring a service provider there is not guarantee that such development will be contributed to the project.

GitHub OSS projects usually manage this via GitHub Sponsors.

See this example.
In this case Alex creates an issue that he is willing to pay for and a developer creates the PR assigning himself to work on it.

That said, the maintainer/petitioner could end not paying or, like Sergi said, there is no guarantee of merging the developers work into the main branch of the project.
A common case that could happen would be if the petitioner requests a new feature while being on the LTS 6.0 but new features are only implemented for the (current) 6.7 branch (6.8 to be).

I think maybe Tryton could provide a bounty wall on the forum once/if the discussion on non-official modules settles. The petitioner would create the issue and the bounty post.