Job badge creation

Hi Technical Team,
I'm facing a recurring issue with job badge creation and would appreciate your help in clarifying a few things. I’ve asked about this a couple of times before (see links below), but unfortunately, none of the suggested solutions have worked:
• https://developer.servicem8.com/discuss/6801498efca1550019df469e
• https://developer.servicem8.com/discuss/67f95b93d3ec71003996de57
I was also advised to refer to the documentation. However, I still have several questions:

Am I using the wrong documentation?
It’s possible I’m referring to an outdated version. Currently, I’m using this one:
https://developer.servicem8.com/reference/get-badge-all
Conflicting API endpoints:
I've received different endpoints in response to my previous posts:
o https://api.servicem8.com/api_1.0/jobbadge.json (shared the first time)
o https://api.servicem8.com/v1/jobbadge (shared the second time)
o https://api.servicem8.com/api_1.0/badge.json (listed in the documentation)
Could you please confirm which is the correct endpoint to use?
Authentication method clarification:
I do not plan to list this integration as a public ServiceM8 app. From what I understand, the main difference between Basic Auth and OAuth 2.0 is related to whether the integration is publicly listed or not. Aside from that, no significant functional differences are mentioned in the documentation.
References:
o https://developer.servicem8.com/discuss/5fffdd46ad49c0007f3fdf69
o https://developer.servicem8.com/docs/authentication
I’d really appreciate your guidance so I can move forward with a working solution.