Can't add SSH Key to the account when using OAuth2 (API has been deprecated)

We are not able to add ssh key via Bitbucket API when we use Oauth2. We use the below API currently for achieving this using OAuth1.
https://confluence.atlassian.com/display/BITBUCKET/ssh-keys+Resource#ssh-keysResource-POST/users/

/ssh-keys

Using the same API, we get the below error when using Oauth2:
"This API has been deprecated and is not available through OAuth2 or JWT"

This is prohibiting our app from switching to Oauth2. Do you have any other suggestions on how we could add ssh key to bitbucket via API.
Our app basically creates the repository and should initialize the repository with some code (hence we need to make a commit)

Kindly provide suggestions. For your convenience, below is link to my request signature and response
https://gist.github.com/svisamsetty/04c80384bb10a1fccc20