Class 2/Class 4 on non-resident

[Brightonian]

I have a client who is non-resident but who has worked in the UK for 5 days in 2025-26. He is self-employed and his profit was £10,000. Does he have to pay Class 2? If he works in the UK again in the current year and earns over the Class 4 limit, will he have to pay that as well? He is resident in Kazakhstan, which does not have a social security agreement with the UK.
Thank you for any advice.