I apologize but I do not see the need to grant such access.
This should be sufficient to find out what has to be done and to issue an advise. Here is the debug log:
An error has occurred.
500 Layout default not found.
/home2/ivelina1/public_html/libraries/src/MVC/View/HtmlView.php:708
Call stack
Function Location
1 () JROOT/libraries/src/MVC/View/HtmlView.php:708
2 Joomla\CMS\MVC\View\HtmlView->loadTemplate() JROOT/libraries/src/MVC/View/HtmlView.php:230
3 Joomla\CMS\MVC\View\HtmlView->display() JROOT/administrator/components/com_templates/views/style/view.html.php:64
4 TemplatesViewStyle->display() JROOT/libraries/src/MVC/Controller/BaseController.php:672
5 Joomla\CMS\MVC\Controller\BaseController->display() JROOT/administrator/components/com_templates/controller.php:73
6 TemplatesController->display() JROOT/libraries/src/MVC/Controller/BaseController.php:710
7 Joomla\CMS\MVC\Controller\BaseController->execute() JROOT/administrator/components/com_templates/templates.php:21
8 require_once() JROOT/libraries/src/Component/ComponentHelper.php:402
9 Joomla\CMS\Component\ComponentHelper::executeComponent() JROOT/libraries/src/Component/ComponentHelper.php:377
10 Joomla\CMS\Component\ComponentHelper::renderComponent() JROOT/libraries/src/Application/AdministratorApplication.php:101
11 Joomla\CMS\Application\AdministratorApplication->dispatch() JROOT/libraries/src/Application/AdministratorApplication.php:159
12 Joomla\CMS\Application\AdministratorApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:196
13 Joomla\CMS\Application\CMSApplication->execute() JROOT/administrator/index.php:51
I guess there is a missing file or a missing database data (undefined cell in a table somewhere or something like this) ... I am sure you can tell me where to look for the problem without the credentials.