depends on the age of the motherboard. many boards needed a bios update to run the 3000 series and then again when the 5000 series came out.
newer stock was updated before it was sold and many can now run even the 5000 series out of the box. most likely since the 3000 series is old enough now, it will work out of the box.
i've built a number of systems in the last 6 months with both 3000 and 5000 series cpu's and only a couple times have I had to update the bios first. I've used the b450/b550 and the x variants. they've pretty well all been ready out of the box.
there is of course the possibility it may not work out of the box and you'll have to flash it first but it is more and more unlikely to happen. look at the box as it will usually have a sticker saying "Ryzen 3000 ready" or 5000 if it's updated for that.