The first is to understand your direction and increase your qualifications. That is, to become a more valuable person. It's worth figuring out what field you want to work in next. It's worth starting to learn new things, to try new places. And all in order to be a more valuable staff, to increase qualifications.
The more a person knows and can do, the higher his salary. This is why if a person is a very good and valuable staff, he is not afraid of losing his job, because he knows that there will be offers from other places. And if the person doesn't know how to do anything in particular, the salary will be small, and a replacement will come very quickly.
Second, don't stay in a place where you are not objectively valued. We get too used to one place of work. This can be actively exploited by employers. They may not give you a raise, may not increase your salary. They will think that the person will not go anywhere anyway. And it often works.
So, if you know for sure that you are undervalued, you should leave, don't be afraid. If you know that a person with your knowledge and skills is getting a lot more elsewhere. It is not worth holding on to one place, especially if you are not appreciated and are not going to increase your salary.
Also, not for nothing I said in the beginning about the choice of your direction, it is also important. After all, if we do not like our job, our specialty, then we will work worse. We will be tired more often, it will be harder to study, and so on. And if we make the right choice, then everything will be easy and fun.
For example, I like psychology and I do not like programming. In psychology I will grow ten times faster. After all, I study it every day with great pleasure, looking for new things myself, and so on. And if I decided to program, I would study and work on schedule as little as possible. So the choice is very important.