Walnut: what you describe is correct for on premise or other cloud services. However, Odoo is still supporting Odoo V13 for a short period of time on Odoo.sh.

Julius: you will need to upgrade your database to version 16 on Odoo.sh before that date hits :)

Hi,

Odoo is providing the support for the last three releases, as of now,the support is provided for 16, 15 and 14, once the 17 is released by this november, the support for the 14 will get end.

As Odoo 13 is released by October 2019, it reaches end of support in October 2022, what you can do now is that, you can update your instance to the higher version like 16.

Thanks & Regards
Walnut Software Solutions