On ne vit qu'une fois - Part 2 Tarkov: Help with the quest

To complete this quest, you must deliver 2 x BNTI Gzhel-K bulletproof vest :

You must first bulletproof vest with a sustainability between 0% and 50% and the second with a durability of between 50% and 100%.

You do not need ballistic plates, as the durability of the vest depends on the condition of its inserts.

Since allied fire is always activated, you can ask a friend to shoot at you to damage your body armor.

If you're playing solo, another trick is to let the edge snipers shoot you. This allows your character to die outside the game zone, and you can collect the vest.

Consider insuring your vest: this will allow you to get it back after about a day if you do it at Prapor, or more quickly if you insure it with La Toubib. You may need to repeat this process several times with the same vest to achieve the required durability.