There is absolutely no problem with your employer paying for anything, but HMRC will consider this to be in lieu of salary and a benefit in kind unless your employer an demonstrate to them that this training is a necessary requirement for your employment duties. I very much doubt this will be the case.
Your employer will have to declare this on your P11D and you will have to declare it on your tax return. I would advise you to take independent tax advice. You may well get a significant tax bill that needs to be factored in. In some circumstances it can be better to increase your salary instead