Report as sole trader as student

Hi HMRC Admins, I am from Hong Kong and am currently studying in an UK university with my BNO visa. From time to time, I may have chance to work on some freelance works (design, copywriting and CV review etc.) and get paid by my individual clients. May I know whether 1. am I eligible to this business activity in UK as sole trader (Based on my understanding, my visa should be eligible to do this but I am told that student is not allowed to be sole trader) 2. If I am not eligible to registered as sole trader, is it still okay to engage in above activities but restricting myself from earning more than 1000 GBP annually ? (I saw the related statement here -> https://www.gov.uk/set-up-sole-trader) Thanks in advance, look forward to seeing your reply

Hi Lok Yiu Yeung,
please refer to Tax on foreign income
Thank you.