I’ve tried a few self hosted options for this, the best so far was Zammad (can host via docker)

That being said I’m also using the free version of Atlassian Jira & Confluence. The free Jira allows multiple projects and then you can use kanban or whatever type of flow. That’s to be honest maybe the easier to manage as the mobile app is pretty good and it’s easy to setup vs Zammad which took a little bit of tinkering.

There is another one I cant recall the name of now, when it comes to me il add it here but it was probably too basic to be very useful.