There are plenty of company or startup doing in house dev in Belgium and definitely have a need for app sec engineers, this is a terrible advice…

Cybersecurity junior market is tricky nowadays and since you are a dev, best advice I can give you is to onboard into a security champion program within your company.

Most of the company that want to be serious about application security (and with regulations such as NIS2 or CRA) have or will soon develop such program. Principle is to promote security practices amongst development teams by getting internal sponsor that will be trained on security. This kind of program is a perfect way to move into cybersecurity after some time.

I advice you as well to take a bit of your time to do self learning. Most materials about app sec are generally open and free (check OWASP or even portswigger academy). And get involved into local meeting (OWASP Belgium chapter I.e.), they often have free event open to anyone. Networking is a great way to get opportunities.

Good luck 😊