Hello,
First thanks for using our Botiga theme!
That’s a default behavior of WooCommerce plugin, that comes with registration form disabled by default.
To enable, please go to Admin Dashboard > WooCommerce > Settings > Accounts & Privacy > Allow customers to create an account on the “My account” page and check the option.
Also you can enable the registration during the checkout, for it go to the same page settings and check the option Allow customers to create an account during checkout.
We hope this helps and clarifies!
Let us know if you have more questions.
Kind Regards,
Rodrigo.
aThemes Support