Custom APP Integration with dynamic fields creation in frontend

I want to create an app which holds an action inside titled "Create/Update Lead". This basically requires user to map their lead_fields with the data source.
A specific user of this app can have different fields so I want a dynamic key-value pair binding of data where key is set by user and the value is mappable to the data from the datasource.

My RAW JSON Structure 1:
{
"fields": {
"name": "{{name}}",
"phone":"{{phone}}
},
"actions": [
{
"type": "SYSTEM_NOTE",
"text": "Pabbly: {{leadSource}}"
},
{
"type": "SYSTEM_NOTE",
"text": "Message: {{Any Other Message}}"
}
]
}

My RAW JSON Structure 2:

{
"fields": {
"name": "{{name}}",
"phone":"{{phone}},
"state": "{{state}}",
"district": "{{district}}"
},
"actions": [
{
"type": "SYSTEM_NOTE",
"text": "Pabbly: {{leadSource}}"
},
{
"type": "SYSTEM_NOTE",
"text": "Message: {{Any Other Message}}"
}
]
}
I want these extra fields like state district be based on add per need basis so that the whole flow works dynamically.

Hey @ankitTeleCRM,

Thank you for connecting with us.

To establish Custom Fields, it is essential to implement built-in actions and configure the parameters accordingly. You will need to select dynamic options within the settings in the front-end and save the test request. I have included this as a courtesy gesture. For additional information, please visit the following link: Learn more
For a comprehensive understanding of the integration process, we invite you to access the following resource: Learn more

If you face any issues do share account credentials and API doc with us our developer will help you set up the event properly.

Best Regards:
Nivesh