After few hours of work and some nerve wrecking challenges. I finally was able to create Laravel OAuth2 using pipedrive. Hope this helps someone in the community.
In case this may be of assistance, this package is good for abstracting the API after OAuth is set up, although some functions are missing:
As another observation, if this is to be a public app, don’t store the tokens in plain text. If you dB is compromised, it is exceptionally valuable information. Encrypt your tables or your model.