Cheap but good Linux certification courses

Hi all.

Hope you're all well :smile:

So I work for an IT company and one of my objectives for the coming year is to successfully complete a Linux certification course. My manager essentially asked me to have a look at what's available; he didn't mention the budget but I guess it would be something fairly cheap as we're a small company.

So I wanted to ask if you all knew of some good yet cheap Linux certification courses available in the UK at the moment, either to complete at a centre or as a distance learning course/ online. Any if there are any Linux distributions that are particularly good to focus on rather than others?

The only course of this nature that I have experience of is the Introduction to Linux (provided by the Linux Foundation) one on edx.org; that would probably fit the bill pretty nicely but I was wondering if there are better/more industry recognised ones that I could explore.

Thanks a lot for reading and for your replies in advance :smile:

Edit= I forgot to mention that I would be looking for a beginner level sort of course; one that aim to teach the essentials.