I'm unable to figure out how to access this option via rest api:
Project settings -> CI/CD -> Token Access -> Allow CI job tokens from the following projects to access this project
Is there anyway to change it via an API rather than using the WebGUI ?
Looks like it can be done from the GraphQL API, see the inboundJobTokenScopeEnabled setting at https://docs.gitlab.com/ee/api/graphql/reference/index.html#mutationprojectcicdsettingsupdate