If you are using a free server plan, you will not be able to disable Minehut cosmetics - however, you will still be able to upload your own resource pack!
If you are using a paid server plan, you can enable or disable Minehut cosmetics by following the instructions below.
If you are using an external server plan, Minehut cosmetics do not apply to your server and there is no toggle to change.
You will see this option listed under Resource Packs in the Settings tab:
You will need to restart your server after switching your preference.