Quiz app reward video

I made an app for chemistry quiz , with airtable it works good now I want to make lifeline like 50-50 that removes two wrong answer from list view .
I m new to modular.please help to how to set blocks for this and also if user don’t have enough coin to use this lifeline thy hav ti see reward video …I want to make this …Please help

Please share blocks…

I just creatd quiz app but not started this and don’t know even how to because I am chemistry teacher not a developer . so anyone know how to use block please suggest me.