Congratulations! You are exactly the same as about 95% of the people who've taken cuttings and are learning how to make clones because you are impatient. That's "OK"; we've all been there. Patience is almost as important as is light, when it comes to growing this fantastic plant!
Firstly, where is the moisture to come from? Spray the dome's (cups) interior. Moisture derived from the (soil) pea pellets will take forever, especially that size. The "humidity dome" is just that. It holds moisture and the spray inside will do the trick. Even this will disappear quickly. Take those domes off and on several times a day and also leave off a bit to get fresh air (CO2) to circulate in between placing it on. The cuttings get their moisture through the leaves and at this early stage, the stem is doing not much more than holding the leaves there. It won't contribute to the plant until the roots happen. Again, Patience here is all important.
I know money is tight, but I strongly recommend you get a starter tray or something to that effect. I just got a kit the other day for $8.00, from OSH, but I'll bet HD has it. It consists of a bottom tray (black) with an inner tray that is divided into cells and has a hle at the bottom for drainage (black also) and then the top is a clear plastic dome with 2 adjustable air vents in it. As far as I know, the only place to get the kit with a tall dome (you need) is from a Hydro store, but HD might have this. I have seen them on eBay for $12.00. Point is that this larger dome accommodates cuttings, the smaller one works great for seeds. The divided cell upper tray helps to hold the individual plants as they are top heavy. Any medium can be used to hold the stem, I favor "Rapid Rooter" plugs, no reason just because. You can flood the bottom tray letting the "plugs/pellets/etc" absorb a bit of water, then drain it out leaving the media saturated but dripping towards dry. Take top off, let fresh air in say 1/2 hr., spray inside of dome and cover them. Leave on 6 hrs. Rpeat 4X daily. The key is moisture, never wet. A very light spray on the leaves also helps. Of course, all the water used is pH corrected. Remember, the only source of nutrient uptake is through the leaves; stems work once roots appear. Until a few weeks AFTER the roots show, no nutrients at all, in any form. Both Rapid Rooter and Peat plugs are nutrient rich to begin with, so any more will fry the cuttings. Light is almost not necessary, I said almost, in fact the darkness encourages root development. Take your cuttings from as low as possible. The lower branches contain far less Nitrogen than the upper, more adventious shoots. Nitrogen discourages root development. Once roots appear, light is far more important (I like the 125W to 200WCFL's U-Tube type). Nutrients be started real weak, like 1/4 strength. Less is better; you can add more; go stronger as your plants tell you to, you'll "feel it" as time progresses. ASK questions; you are off to a good start. Good luck, lots to learn here... God, I hope I got it down in a useable form; I tend to diatribe and for this I apologize...