CELTA is the qualification if you want to teach English as a Foreign language (used to be called CTEFLA).
It does look as though it can be done partly on-line now, but has to have a significant teaching practice element. No teaching practice, and the qualification is just toilet paper.
I can't post a link because apparently I can copy not paste (technical issue :o ) but just google CELTA - it's the "gold standard" entry level qualification. It can be done full time in 5 weeks or part time over up to a year. Plenty of people go on to do post grad diplomas and MAs in TEFL after that, but you need CELTA to get your foot in the door.
I assume he as a degree? Again he won't get a job anywhere reputable without a degree.
There are so many people wanting to teach EFL nowadays, it's no longer enough to be a native speaker who has done a token course. As I say even with qualifications and experience, most jobs are not actually jobs but positions for self employed contractors, with the exception of the head of the language school and some admin staff.
If he does have CTEFLA and a degree it is incredibly easy to get work through one of the big chains line inlingua in most European countries, but on a self employed basis. They usually pay enough to live on but not enough to save up, and of course you have to pay all your own tax and health insurance, pension contributions etc.
If he just wants to be in Spain (is that where you are) he'd do better to move out and then apply to all the language schools in person - they certainly won't pay moving expenses or any kind of ex pat package because they've no need to.