Hello,
Thanks for wp-admin access.
Settings > Permalinks > check if you use the Post name type http://prntscr.com/s7zqco and re-save permalinks. Clear cache and check then.
If this doesn’t help, try to disable all the third-party plugins (including cache plugins), that do not come bundled with XStore https://xstore.helpscoutdocs.com/article/36-included-plugins , clear cache of browser, and check then. Maybe one of the additional plugins is a reason for the problem.
If this is not permalink settings, and it was not caused by plugins, provide FTP access. Contact your hosting provider and ask for FTP host, FTP username, and FTP password.
Regards