can't open state owned website due to sertificate signature error

Hi, I try to use Firefox for my job and faced with the problem that I can't open state owned website due to sertificate signature error. I ready to take a risk but I can't find the button "Proceed.. (Risky)". This button simply not showing. In th same time in mobile version I saw this button, could take permssions myself and open the website. I tryed to add root and sub sertificates of the Goverment, tryed to add the site address to exclusions -- all these steps don't work. I can't open the site and can't find button "Proceed.. (Risky)". Moreover, in the same time, I can open this website without any questions and problems with Safari and Chrome. I use the last Firefox version (153.0) from Firefox official website. How can I resolve this problem in Firefox? Please help me