To get specific plant from inzanity and random level (for example get sunflower from Ancient Egypt), when you complete the task and claim the pinata (if the pinata isn't seed plant do you want), just click/tap back button when the task said "completed" before it vanished, after that you can check quest log and you gonna see that task still said "completed" (keep doing it untill you get specific seed do you want)
Note : if you click/tap back button before the "completed" task vanished, the previous reward won't be add to your account, only last reward you claim will be add to your account
for example 1st try : Tangle Kelp x10, Banana Launcher x 5, Hot potato x5 (it won't be add to your account)
The last one (specific seed) : Sunflower x5 , Bowling Bulb x5, Pepper-Pult x 10 (will be add to your account)
*work for multiple device (just doing untill get one mark/ ✔ to one device, switch to another device and complete it, after that complete it from your previous device)