Thank you very much for the answer!
I wanted to use this particular rig, because the "eye" of this creature is very complex and some elements are uncomfortable for weight painting. I myself will not be able to repeat such a rig from scratch with the use of sl bones, so unfortunately so far I have to abandon this idea... So sorry...
If there was some other way, for example, to add the missing bones to the existing rig - it would be just fine!