I have a 2018 Trek Domane with 105 11 speed on it, you can fit an 11-34 cassette and that will work well enough but it's pretty much the edge of the capacity for the rear derailleur (medium cage, so GS) in it's standard configuration.
You might be able to fit a wolftooth road link or similar and extend the rear dropout to fit a larger rear cassette like a Sunrace MS8 11-40 cassette which would massively extend your lower gear. But you need to be more considered around shifting with these larger cassettes as you'll hit the capacity of the derailleur earlier if you don't shift down and a slightly longer chain will mean more slack when you're in a higher gear so drivetrain noise might rise a bit.
You don't say what crankset you have, but I'm assuming Shimano, so the alternative might be to swap that for a GRX 2x11 46/30 which would also lower your bottom gear significantly. Keeping an 11-34 cassette would be a similar range to the 11-40 cassette with probably a little bit less hassle other than repositioning your front derailleur (slightly lower and a little further out most likely).
A comparison to all three options is
here.