Modify an Question Bank Feature of an LMS from CodeCanyon

Hello everyone, Summary: I've a very simple and urgent project for you guys. You've to suggest me an already built LMS from codecanyon etc. and then make some modifications in its Question_bank_feature. So, it involves 4 phases. Phase 1: LMS recommendation (meeting some conditions) Phase 2: Question bank modification-part1 (Add Questions modifications) Phase 3: Question bank modification-part2 (Questions filtration/search modifications and csv, excel, json export) Phase 4: Question bank modification-part3 (Details yet to final) Phase 1 details: Recommend an already built LMS system that meets the following conditions (conditions with price $00 are COMPULSORY): 1. + $00 -- Easily customizable 2. + $00 -- Has Question bank system with Mathjax support 3. + $05 -- Has backend on Firebase -- (else you’ll transfer from other backend to firebase for $10) 4. + $30 -- Supports branching system (What I want is: I’ve LMS installed in my website and I offer a few services for institutes in there. The institutes, instead of buying LMS for their websites, will buy subscriptions on my website. This way, they will get all features of LMS from my website by creating an account + additional services I’ll provide to them) – 5. + $10 -- Price is less than $60 from codecanyon etc. (however, the maximum price allowed is $80) Other phase details: Will provide in private to short-listed freelancers only. Payment terms: 1- Each phase (except phase 1) is worth $50. Total project amount maximum $200. 2- We'll proceed phase by phase. On the project award I'll create $50 as milestone. However, the first milestone payment will be released only after completion of phase 2 (because only LMS recommendation and later not able to customize will waste time and money). You'll provide regular updates and when the phase has been completed, you'll provide me complete source and I'll release that amount and immediately will create next $50. 3- NO UPFRONT PAYMENT, I've had very bad experiences in the past. So no more risk. 4- Your bid amount should be $200, no more, no less. Otherwise your bid proposal will be simply ignored. Do you have any questions, feel free to ask. Your proposal should state solution and insight to the project requirements and how you plan to finish it. Your bid should include a link to a codecanyon LMS system that is close to phase1 requirements, so that I know you've read details carefully and not a spoiler. NOTE: Once accepted, you'll finish all phases (up to 4) till completion. Finish this project within 10-12 days. Thanks very much.