Valvoline ATF + 4 is a uniquely blended automatic transmission fluid that meets Chrysler Material Standard MS-9602.
Walmart Supertech meets this standard, Castrol does not (it doesn't have the same 'machine oil' odor).
Many filter kits come with a rubber or cork (obsolete) pan gasket and seal. The factory and dealers use an ATF-proof RTV. Other RTV formulas may break down and leak. Read the labels. There should be no need for additives.
You probably don't have a dipstick and if there are no oil leaks, you should be able to fill it with the same amount that came out (about 5 quarts/liters).
I use an old section of speedometer cable for a dipstick and go by the temperature/fill graph (about 12mm @ ambient). Listen for the light cable 'thunk' at the bottom of the pan and go no further.
The video missed one step in replacing the filter. The filter will come with a new seal that is inserted into the valve body. It may not be necessary to replace the seal as it grips the filter firmly (you will noticed this in the video when he is removing the filter). To replace the seal, you need to pull it out. The best tool to do this is a 'lady foot' that goes through the seal and hooks to the upper edge.
I differ from the video in that I remove the lower bolts and loosen the upper ones so I can fully release the lower edge and let the pan 'hang' from the upper bolts and drain from the lower edge.
One of the best ways to assure the oil level is correct without a dipstick, is to accurately measure what you take out and add only that amount back. A single 5-quart jug will likely not be enough as the refill is more like 5.5 quarts.
You can never rely on the amount drained out to be the right amount to put back in. How would you know if its at the correct level to begin with? Also its a bit hard to measure the amount unless you have a drain plug where the fluid won’t drain all around the pan and spill on the ground. The engine oil dipstick also works. Just measure the end and use the chart. Use an infrared temp gun on the pan to get a temp reading