Web3 - smart contract - presale token web

I have the half of the project done, I just need some functions on the user area that is not working properly, and you need programming the admin area complete. I have Metamask working.
Furthermore, I can provide access to the site to you check it our advances.

The site is working now under Lavarel.
I have 5-7 Days Max for this.

Basically, what the company does is, for example, we show to our users, crypto project which will be released soon, so they can invest in their seed round, so our users can receive from those company tokens of the project in a cheap price.
- 1000 users see a crypto project to invest in.
- Using Metamask they invest in the projects that we show them on the web, using a stable coin (BUSD).

- We receive 1,000 transactions in the amount of 100 to 500 BUSD.
- We accumulate all the money, and then we buy the tokens (on the same blockchain / Binance Smart Chain)
- When we have all the tokens, we must send it to all users their tokens, depending on how much they initially contributed.
- If a user-contributed $100, he will receive a different amount of tokens than someone who contributed $200 and so on.

- We post 6-8 crypto project to invest per month.
- Site should be code thinking we will receive 10K-30K transactions per months. So maybe a smart contract here could be a great idea.