Follow these instructions to create a new API by uploading an Open Proxy Specification file.
See Open Proxy Specification for details about the Open Proxy Specification format.
Navigate to “APIs“ in the menu on the left side.
Select “Create New API“ from the menu in the top right corner.
...
A dialog will open, that will guide you through the API creation process. Make sure to select “Create new API from specification files”. Use the Left “Choose“ button to select your Open Proxy Specification file. Optionally, you may also select an API Specification file (e.g. Open API) for documentation. If you omit the API Specification file here, you can always upload it later, after API creation has been completed.
...