When I notice something wrong how do I go about getting the issue fixed?

Linux and its software is constantly under development and the community seems to really be making an effort to ensure that programs work exactly as expected. I often notice little things like glitches or program crashes and I am able to replicate them and I think I should probably submit a bug report or something. Since I am not a dev I have no idea how to do this or where to start. How do I know if its my issue or the programs issue?

For example, Thunderbird 115.1.0 is crashing when I open a specific email. I will put the steps I took to debug it in the comments.