Using API calls detailed in this link, you will need some required parameters, please check below how to get some of these parameters from your account.
API Key
Go to Settings -> API integration.
List ID
Go to the list page, and you can find the List id in the URL.
Field ID
Go to your List Form preview.
Right click on the field -> Inspect, and you can find the Field ID in the line code.
You can also get the IDs (List and Fields) using this API call.
Contact ID
Open the Lead profile, you can find the contact ID in the URL.
