Hi AatifNazar,
as far as I know it is not currently possible. See the following posts:
- Adding Issue Field to project create screen with REST API
- https://community.atlassian.com/t5/Jira-questions/JIRA-API-Create-Issue-with-custom-field/qaq-p/1126615
You can create a custom field context https://developer.atlassian.com/cloud/jira/platform/rest/v3/api-group-issue-custom-field-contexts/#api-rest-api-3-field-fieldid-context-post and then assign it to a project and issue type, but I suppose this is a different use case.
Cheers
Vojtěch Schlemmer [MoroSystems, s.r.o., Czech Republic]