When I became a "professional" software developer around six years ago, I thought quite a lot about my job title.
I wanted to be "Fullstack" and, at some point, I wanted that "Senior" prefix.
Since then, I've had lots of job titles including Senior Fullstack Software Engineer.
If you're reading this and you're not applying for the job you really want because you don't think you're ready - it's ok to not know everything.
I consider myself a backend engineer that can do frontend when needed, and I've been employed several times as a "Fullstack" engineer. If you asked me to make a simple CSS animation or a responsive HTML webpage - I'd be going straight to Google, because I simply don't know how to do frontend from memory.
But, do you know why these companies employed me anyway? Because they don't care if I can write a website, from scratch, from memory, or if I do it by searching the web - because it's ok not to know everything.
I learn quickly and I can pick things up, that I've never done before, with minimal assistance. I wasn't given the job because I can retain loads of information, truth be told my memory is shit, but because they can give me a job and trust that I'll do it.
I'll say it one more time:
It's ok not to know everything
If you're competent enough to get through a task using Google, you're ready to start applying.