Where to get access_token when testing RestApi with Codeception?

Question

PHP

I came across such a thing, all my api is closed for unauthorized users, so you must first get a token.
That is, before all the tests, you need to execute the code, get the token, put it in the amBearerAuthenticated method and run all the tests.
As I fields all tests should be executed in any order and not depend on each other.
I can get the token in every test in the _before method:

class GroupResponseCest
{
    public function _before(ApiTester $I)
    {
        // получить токен
        $I->amBearerAuthenticated($token);
    }

    public function all(ApiTester $I)
    {
    }
}

However, then the base is clogged and constant duplication of code. There is also a _bootstrap.php file, but I did not understand how you can get methods for requests to api from there.
Please tell me how can I get a token immediately before running all the tests?