That’s how I became popular with the ladies when I went to band camp. I had extreme social anxiety about starting conversations with girls, so I bought a ridiculous hat in the French Quarter in New Orleans. Because I could wear that around them with no trouble for some reason
I didn’t have to initiate any conversations that year, they all came to me.
No, there’s no legal requirement to contribute to projects you’ve used and modified, unless the license explicitly states so.