Connecting Seeeduino XIAO 3.3 V out to dual H-bridge driver module (L298N) with TTL compatible inputs
Am I correct to assume that I do not need to step-up the logic signal (from 3.3V to 5V) for this to work, but can connect straight to the input?

You are correct. The input has to be above 2.3V to register as HIGH and below 1.5V to register as LOW. You have 3.3V for HIGH and near 0V for LOW, which fits those criteria perfectly.