Route "system.db_update" does not exist

Hello everyone,

I'm running a Drupal site and trying to update my site on v8.7.10, I have no access to the site after loading the files on my server.

Here is the display on the index.php

The website encountered an unexpected error. Please try again later.
Drupal\Core\Database\DatabaseExceptionWrapper: SQLSTATE[42000]: Syntax error or access violation: 1142 INSERT command denied to user 'cgtcaenfydjean27'@'10.4.107.7' for table 'watchdog': INSERT INTO {watchdog} (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9); Array ( [:db_insert_placeholder_0] => 0 [:db_insert_placeholder_1] => DrupalKernel [:db_insert_placeholder_2] => Container cannot be saved to cache. [:db_insert_placeholder_3] => a:0:{} [:db_insert_placeholder_4] => 3 [:db_insert_placeholder_5] => [:db_insert_placeholder_6] => [:db_insert_placeholder_7] => [:db_insert_placeholder_8] => [:db_insert_placeholder_9] => 1575201981 ) in Drupal\dblog\Logger\DbLog->log() (line 78 of core/modules/dblog/src/Logger/DbLog.php).

and on my update.php that I could not launch:

The website encountered an unexpected error. Please try again later.
Symfony\Component\Routing\Exception\RouteNotFoundException: Route "system.db_update" does not exist. in Drupal\Core\Routing\RouteProvider->getRouteByName() (line 201 of core/lib/Drupal/Core/Routing/RouteProvider.php).