Hi,
If you are dropshipping goods from the EU to the final customer in the UK, there will be different scenarios depending upon the value of the goods.
If the goods are over £135 and you are the importer of record, then you are making a taxable supply in the UK. If your company belongs in the UK then you will need to register for VAT once you breach the £90K threshold. If you are based overseas then you would need to register for VAT straight away. If your customer is the importer then you will not be making a taxable supply in the UK.
If the goods are below the value of £135 then please see the guidance here:
Changes to VAT treatment of overseas goods sold to customers from 1 January 2021
Thank you.