If the festival or season you are applying to takes a registration / application or marketing fee then this will appear in the Payments section in your event registration forms:
You may see a downloadable invoice in this section - this is for your records.
You will be prompted to make an online payment when you complete the required questions in your forms - this might be once you've completed the application phase:
In most cases you will be prompted to make payment when you are ready to finalise.
You will see the finalise button under the festival / season logo - it will be orange when everything is 100% complete. Click on it, agree to the festival/season terms and conditions, see which answers will appear in print or online and make payment: