How do i save a base64 decoded image to file_managed?

I'm trying to save my image to Drupal's file_managed table. However, my image is coming from base64 decode:

 $filename = "sign-".$user->id(); // returns "sign-1234"
 $image_raw = $form_state->getValue('signature'); // returns base64 string of png
 $data = base64_decode(preg_replace('#^data:image/\w+;base64,#i', '', $image_raw));
 $image = file_put_contents('private://requestformfiles/'.$filename.'.png', $data);

 $file = File::load($image); // does not get anything
 $file->setPermanent(); // fails
 $file->save(); 

 $result = $connection->insert('request_id')
        ->fields([
            ...
            'signature' => $image,
            ...
        ])
        ->execute();

From what i see, My file successfully uploads into the private files folder, and image returns a random 4 digit number. However, when setting it to file_managed in the Database, it fails, since File::load cannot see my $image.

Any help is again, appreciated.

I actually didn't have to use File entity for this, what i actually needed was file_save_data()

$filename = "nrsign-".$user->id();
$files_data = preg_replace('#^data:application/\w+;base64,#i', '', $image_raw);
$file_data = base64_decode($files_data);
$file = file_save_data($file_data, "private://requestformfiles/".$filename.".png", FILE_EXISTS_RENAME);

echo $file->id();

file_save_data creates the file and saves a record in files_managed as well. $file->id(); returns the $fid for the created file.