Important: #69846 - Have eIDs with PSR-7 without ControllerInterface 

Description 

In order to allow the same logic as with the routing and the direct information which method to call, implementing ControllerInterface is not mandatory anymore.

Remove the implements ControllerInterface instruction in the affected class. The former processRequest method may (and should) be changed to:

public function anyMethodNameYouLike(ServerRequestInterface $request, \Psr\Http\Message\ResponseInterface $response) {
}

Please note that the $response object is now passed into the method directly, thus you must not create a new object by $response = GeneralUtility::makeInstance(Response::class); any more.

The eID_include registration in ext_localconf.php must be changed in such case to

$GLOBALS['TYPO3_CONF_VARS']['FE']['eID_include']['identifier'] = \Foo\Bar::class . '::anyMethodNameYouLike';