filemtime error

[Jcs1994]

Hi
i'm trying to verify a token using this documentation https://auth0.com/docs/quickstart/backend/php
but I get an error with filemtime (I'm on a php docker container).

I don't understand why I get that error ? the folder cache has all permissions

          $cacheHandler = new FileCache('./cache', 600, 0777, 0777);
          $token_issuer = 'https://' . getenv('AUTH0_DOMAIN') . '/';
          $audience = getenv('AUTH0_AUDIENCE');
          $jwksUri = $token_issuer . '.well-known/jwks.json';

          $jwksFetcher = new JWKFetcher($cacheHandler, ['base_uri' => $jwksUri]);
          $sigVerifier = new AsymmetricVerifier($jwksFetcher);
          $tokenVerifier = new TokenVerifier($token_issuer, $audience, $sigVerifier);

          $this->tokenInfo = $tokenVerifier->verify($this->token); // error

ERROR: Type: ErrorException; Message: filemtime(): stat failed for /var/www/html/cache/8/C/17c2f21a0d8a2cd6390573cd2b18a249fd508ba68a173de85e871174f9b487; File: /var/www/html/vendor/kodus/file-cache/src/FileCache.php; Line: 81; [] []