i.e. is there actually demand for Cybersecurity? A gap is not the same as demand. Maybe it shows they just don't care.
1) application security engineering 2) application penetration testing 3) devsecops 4) vulnerability management
It really is a big difference from each person on how they "break into" it. You've got great foundational qualifications, and probably just need to layer on extra "security" ones, if you don't already have them. If you're looking to start a company / start freelancing -- I've got no clue about that though.
If you're just dipping your toes further into the web app security side, OWASP has great labs, resources, etc. They have the WSTG (more for pentesters) and ASVS (more for devs), and of course their cheat sheets as well.
PortSwigger has great resources to read through on vulnerabilities and labs that will cover a ton of different vulnerabilities. HackTheBox also offers certification pathways: CBBH and CWEE, CBBH is more beginner/intermediate and involves a blackbox approach, where CWEE is more whitebox (from what it looks like).
Just because systems have gaps, doesn't mean the orgs actually want help with those gaps, esp. unsolicited. You could always take a look at bug bounty as well (through HackerOne or BugCrowd), but it can be pretty brutal for a beginner as it can involve a ton of recon or "going deep" to reach untouched areas of an app.
In my opinion, cybersec/infosec expertise/mindset should be always-on on everybody at 2025. Starting from scammers calling/messaging, to malware/spyware on devices, social engineering, physical security, people security/trustworthyness, trust/auth/integrity/encryption/backups/certs/audit-trail etc... Everything. One needs to know if one is hacked already ("Reflections on Trusting Trust.pdf"), and one needs to know when one is hacked (tripwire). And knowing what is/are your weakest link(s), because it usually defines the strength of your defences.
That's how a friend did it. To be fair, he's Dutch and did this with Dutch companies. So not sure if this would work in your country.
https://portswigger.net/web-security is a great resource to get you started.
Good luck!