@Expee If its a new printer and has been working OK for the last few weeks, do not use glue or any other kind of layer on your bed. Basically, if it wasn't necessary during the last few weeks, it shouldn't be necessary now!
The bed may need cleaning, especially if you have been touching it with your fingers. This is best done using a small amount of Isopropyl Alcohol (99.9% Pure IPA) with a clean cloth. When the printer is not in use, cover the bed to stop the build up of dust, and/or gently wipe the bed with a clean cloth before use (...don't wipe the surface with your hands!).
If you have been printing with the same filament for the last couple of weeks, and have left the filament on the printer between prints, it may have absorbed moisture from the air. This may affect its performance & ability to stick. I suggest you invest in a cheap digital hydrometer. Keep an eye on the relative humidity and avoid leaving filament reels out if the RH is greater than (say) 50%.
Silica gel is great for storing filament, but it is not a magic solution; every time you take out a filament reel and subsequently put it back into a storage bag, you change the air in the bag. The silica gel then very slowly absorbs some of the moisture, as long as the silica gel is not saturated.
Check and clean the outside of the nozzle to ensure that as plastic is extruded, it is not sticking to the nozzle. Also make sure that there is not a bead of plastic on the tip, as this will give you problems when trying to level the bed.
Investigate non-stick problems by printing small objects (i.e. those that can be printed in a short time; say, <20mins). Do these test prints near one of the front corners of the machine; this is because it is easier to make adjustments to the leveling on one corner than it is when you print in the centre of the bed. If you can get it to stick in a corner, you should be able to fully level the bed and then it should stick in the centre (...actually, I don't print anything in the centre of the bed, unless it is a very large object).
I hope this helps.