Hi, please I can’t find how to renew default rests in particular bars. Via picture.
. Thanks Jiri
Double click at the start of the measure to invoke the caret there, then type Shift-B rest Enter.
Jiri: also, welcome to the forum. 
Ah yes, that too - welcome Jiri!
Thanks a lot for all. Solved👍
On a slightly similar vein… I recently tried to create a bar in a combined cello and bass part with notes in the cello and a [mid-bar] whole-bar rest in the bass part, but I was unable, without a workaround, to find a way to do this ‘properly’. I ended up copying a half-note rest for the bass part and placing it on the half-bar, which created another half rest at the beginning, which I hid. I then changed the vertical position of the half rest to make it look like a whole rest. There must be a better way!
You can only do Shift-B, rest, if there’s already a downstem voice in use in that staff.
This worked but, of course, not initially, as there was at the time no second voice. After I later had had a need for a second voice, I was able to go back and use Shift-B, rest and redo this ‘properly’. If I’d had no need for a second voice, I would either have had to settle for my workaround or to have created a fake second voice somewhere and camouflaged it. This isn’t that rare an occurrence so it’s strange that this particular situation is difficult.
Vaughan, you don’t need to fake anything or hide anything. You just need to make sure that the second voice actually exists. Look:
Ah, thanks again, Leo!