How to start asking for small fee?

I've been volunteering for a while to take film photos at local parties and events, and I've reached a point where organizers would reach out and ask me to "pop by and take some photos"
They would offer to cover film costs, and obviously I would get guest list for the party. However, I would like to start making a living from it and do not know the right way to go about and ask for a small fee, even if it is around 50-100€ for the night. I feel like it is complicated because it's a relatively small scene and I'm starting out, also feels lime I am building some relationship with these organizers and they're not total strangers.. Also with them offering to pay the film costs it maybe gets more complex for me to ask for more?