Ruling on subscribing to confirm online sales on Amazon for a fee
Question

I joined a digital project for a certain fee. The aim of the project is to confirm online sales for companies such as Ali Baba, Taobao, Amazon and so on. You earn a certain percentage for every confirmation of a sale, and this is limited to no more than fifty transactions every twenty-four hours. If you do not confirm the sale, you will not get anything. I will explain to you how it works: the more you invest, the higher the price of the product of which you confirm the sale will rise. In other words, you will earn a specific percentage for every sales transaction. Moreover, your level will rise every time your capital reaches a specific amount. For example, the first level is less than five hundred dollars as an investment + inviting five friends to join. The second level is greater than five hundred dollars as an investment + inviting ten friends, and so on and so forth. I am working by myself, without inviting any friends, and I am content with the first level. What is the ruling on working on this project?
Praise be to Allah.online sales works for the online stores you mentioned.
But as it is stipulated that you must pay a subscription fee in order to be able to show likes or to click or confirm, then this is haram, because it is gambling, as you pay money in the hope of getting more, which may or may not happen. Gambling means certain loss and possible gain.
Al-Bujayrimi (may Allah have mercy on him) said: Gambling is something that is done with the possibility of either gaining or losing." (Haashiyat al-Bujayrimi ‘ala Sharh al-Manhaj 4/376).
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: Gambling – which is any transaction in which there is the possibility of either gaining or losing, and the one who is involved in it does not know whether he will be a winner or a loser – is haram in all cases. In fact it is a major sin, and it is obvious to anyone that it is reprehensible when he sees that Allah, may He be exalted, mentions it alongside idol worship, khamr (intoxicants) and divining arrows." (Fataawa Islamiyyah  4/441).
Moreover, this money that you pay cannot be regarded as a permissible kind of investment, because it does not meet the conditions of investment, which are: that the field of work should be permissible, there should be no guarantee of the capital, and the gain should be a percentage of the profits, not of the capital or a set amount.
In this case, if you will not get the capital back, then what kind of investment is this?! Rather it is gambling, as noted above.
If the capital is guaranteed, then the investment is invalid according to Islamic teachings.
If the gain is not defined as a percentage of the profits, then the investment is also invalid according to Islamic teachings.
Conclusion
This is a haram transaction and you must refrain from it. If, in addition to that, it is required to invite others to join, then it is even more haram.
And Allah knows best.