In case of being CAS (AV ČR) employee, VERSO credentials are all you need to log in – see below. http://metavo.metacentrum.cz/cs/application/index.html

Scroll down, until you find your Institution (ÚŽFG as an example here).

Application form follows – fill it in and submit.

A confirmation email arrived:

děkujeme Vám za registraci do virtuální organizace MetaCentrum. …
O schválení nebo zamítnutí přihlášky budete informován(a) dalším mailem.

Here is whad have I done last year, since I did not had the password … http://eis.cas.cz/

I have tried it by Personal number – it is on payroll and on confirmed travel orders.

Finally I retrieved it through my email address.

Here I entered my university email, since I do not have academic one (@cas.cz)… firstly it complained several times something about “address is not in database”, but then it yielded… nevertheless an email arrived promptly and after clicking, a password appeared.