If you want a way to make some more money, then you could do this by monetising your hobby. This can be more fun than other jobs and so it is worth considering. There are different things that you can do which might allow you to make money from what you do.
Sell Items that you Make
If your hobby involves making things then you could think about whether to sell those items to make money. For example, if you paint, knit, make lace, weave or even bake, you may be able to sell the items you make. This could be done through a website that already exists such as Etsy, but also through your own website or even a stall at a market. It is worth thinking about whether you feel that you could produce enough items to be able to sell and how much you might be able to sell them for. It is a good idea to have a look at what other people are selling first and think about whether there is a gap in the market and if you could make enough money to cover the costs and make a profit. Often crafts are sold very cheaply and it is hard to see how sellers can make enough money to even cover their materials, so watch out for this as there is no point in doing it if you will be out of pocket.
Write a Book
It could be fun to write a book about your hobby. If you enjoy travelling, for example, writing a book about your experiences or with tips to travellers or something like this could be useful and fun to do. Obviously, books are pretty long and so you will need to spend quite a bit of time on it and you will also have to think about the publishing of it. You will need to either find a publisher or self-publish, which is something you can do easily and then you can sell self-published books through Amazon as e-books and they do a print on demand service as well.
Create a Website
It could be that you might want to create a website about your hobby. There are lots of free resources you can use these days to create a website easily. You could then sell items through the site, use affiliate links or other ways of advertising to raise some money. It is not easy to raise money this way as you will have to promote the site and get people looking at it, but if you can promote it on social media that can help.
Make a YouTube Channel
This is a similar way to raise money to a website but you will need to make videos to publish to the site. This is something that you will be able to do with a phone or other mobile device. You may need some editing software but there are free ones available that you can use. You can use affiliate links in your descriptions and you can also have advertising on the videos once you get enough subscribers and viewers.
It can be fun to teach other people how to do your hobby. Running a local class or an online workshop which people pay to attend can be a good way to make some money. This can be a lot of fun as you also will get to join together with like minded people. You will need to be confident that you can teach and also be able to find a suitable venue and advertising to get enough interested people to come along.