Prior to 2021, if you were a dropshipper using a Chinese supplier, e.g. AliExpress, then these were considered out of scope for UK VAT. Have a read of our VAT for Dropshippers post for a more detailed treatment.
After 1 January 2021, new VAT rules apply for sales for sales to the UK, and the EU is bringing in similar changes in July 2021. Take a look at our post on VAT changes in 2021.