Please read the details in this link:
https://www.rusemb.org.uk/consnews/109
We can now assist UK nationals and UK permanent residents to obtain their visas. EU nationals must provide Blue residence card. However, the Russian Migration service has not yet resumed the issuing of business invitations. We are trying to establish when services will fully re-open. Please be patient with us. We will update the news section as soon as we have more information.