The url is eshubham.com running 1.53 version of Zencart and PHP 7.4.

Around June 2020, we migrated from older version to 1.53 and was working fine till recently. I didnt logged into admin dashboard for last three months. Just last week I tried to log in so I can put the website under maintenance to upgrade the zencart but it showing too many redirect error. I contacted my hosting support team, they are certain that .htaccess has no issue and contact zencart support for further assistance. I am new here. Please guide what should I do for troubleshooting.