Yubikeys has two slots, slot 1 and slot 2, that slots can program as a Yubico Format Output or as a HOTP (6-digit OTP)
Configure the yubikeys as is shown in the video, but select slot 2 for the 6-digit HOTP, in this way when you touch, the yubikey send the slot 1 OTP, but if you touch the yubikey for more than 3 seconds, the hardware sends slot 2
Now you can use the two slots!