On the Shop Manager page click "View Store" in the Shop Manager menu.
Then copy and paste the link from the browser address bar.
When using a phone you can copy your link as follows:
On the Shop Manager menu, press and hold on the "View Store" link then tap "Copy Link Address".
You can do the same with any link on the site.
Your shop link will be in the following format:
https://mademe.co.uk/shop/yourshopname/
If you have spaces in your shop name, e.g. your shop name, then replace the spaces with hyphens (-):
https://mademe.co.uk/shop/your-shop-name/