Check to include prompts if desired, but only embeddings and loras from the positive prompt will be used. If you want to include any other text, you will need to type it into the form.
Click Parse Metadata to convert metadata into the form.
Edit or add any optional fields.
Name your preset and generate the JSON file.
Download the JSON file to your Fooocus/presets folder.
Hit Refresh All Files in the model tab to see your new preset.
There are some optional fields that you can add as well but are not required.
If you often use many Loras it is best to make sure you start Fooocus with a preset that has this setting to a higher amount since the max amount of Loras cannot be changed without restarting Fooocus.