At the stage you are at right now, if no sprouting tail or crack is visible, I usually crack it myself between my teeth (carefully!) and place it back in the soil.
BUT. For seeds this old it is usually best to pasteurize the starting soil by taking the amount of soil you need and pouring boiling water on it 2 times and then letting it cool. Once is probably enough even but I do it twice to be sure it has all gone hot enough.
After it has cooled completely, you pack the soil tightly together in your hands until only a few drops can be pushed out. Then you crumble it up again so it’s a friable texture.
At this point you can choose to inoculate the soil with life that is helpful to cannabis like startrex or some other live inoculant (is available online from many cannabis-oriented nutrient brands).
Lightly press the soil down so it’s a little compacted but still light and airy (I always add a lot of perlite in my seed starting and cutting mix, this helps both seeds and cuttings to establish a nice rootmass very quickly). Take a toothpick and make a dimple for the seed, drop it in, cover again, and then, you add a couple drops right on top of where the seeds are, of my top secret ultra refined germination enhancing BONGWATER!
I’m not kidding. Bongwater helps germination. Think of it as the seeds getting a signal that life above ground has burned down and NOW is their chance to repopulate the world with resistance/competition from other species being brought to a minimum.