I'm having trouble installing mdbootstrap-pro. When I run $ yarn install I get the following error.

yarn install v1.19.2
[1/4] Resolving packages...
error Command failed.
Exit code: 128
Command: git
Arguments: ls-remote --tags --heads https://oauth2:○○○○@git.mdbootstrap.com/mdb/jquery/jq-pro.git
Directory: /sample-app
Output:
remote: The project you were looking for could not be found.
fatal: repository 'https://oauth2:○○○○@git.mdbootstrap.com/mdb/jquery/jq-pro.git/' not found
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.

package.json

{
    "dependencies": {
        "mdbootstrap-pro": "git+https://oauth2:○○○○@git.mdbootstrap.com/mdb/jquery/jq-pro.git#4.9.0"
    }
}

I am developing with Ruby On Rails, and I hope this probrem will be resolved soon.Thank you in advance.