CE and UKCA Certificate and declaration of conformity

Amazon sent the below email to me asking to submit the EU declaration of conformity certificate. how can I make one?

what is the procedure to get CE and UKCA certificate for my toys. Can somebody help the best way?

Hello from Amazon,

We are contacting you because you have listed products that require you to submit compliance documents. Click View Compliance Requirements below to see the list of affected products and submit the required compliance documents. If you do not submit the documents by the due date indicated for each product in this link, we may remove the affected listings.