Correct method to transition from snapshots to milestones

[candiesdoodle]

There is an issue with the repository that keeps resurfacing for some reason.
You can refer to the steps here:

Guide: Installing and testing OH3 snapshots/milestones using APT and YUM

Hi all, .DEB and .RPM packages for openHAB 3 snapshots and milestones (3.0.0.M1) are now available. I’m going to use this space to detail what’s changing and how to use them. If anything changes with the packages I will update this post. Note for openHABian users: openHABian has a few extra features such as zram that use openHAB 2 specific paths. If you want to try openHAB 3, you should disable ZRAM first and expect that there will be a few things (such as frontail) that will not work as you’d …

@Benjy

If you have trouble connecting to the repo with an error that looks like:

Unknown date format Bad header data [IP: XX.XX.XX.XX 443]
then in place of the install command, you can use the file directly e.g.:

wget JFrog
sudo apt install ./openhab_3.0.0~S1919-1_all.deb
For later versions than the example above, the list of versions can be found here