Opinion ! Affiliate Marketing

I'm currently on a tier 4 student visa in UK, which only allows me to work 20hr term time under an employer and restricts me from doing any business and being self-employed, as I'm assuming for tax reasons. However, I've been thinking of doing affiliate marketing and I've tried to search the tax implications of affiliate marketing, all of which seems to tell me that I can pursue this area without worrying about my tax returns since the tax is automatically deducted from the seller/buyer I affiliated with (until the income I get from affiliate marketing reaches a certain threshold?). Has any international student here considered or done affiliate marketing and do you know if it's possible for me to do it? I obviously do not want to get in trouble with the law and potentially get deported back out of my recklessness.