Proving partnership in a company without a written proof

A friend and I have started a business in Dubai about 2 years back and I paid my share of the capital and expenses on that basis we'd be 50/50 partners.

The company was registered under an Emirati sponsor as per the local laws and regulations who holds 51% of the shares and my friend who holds the remaining 49%.

We didn't add my name to the application at the time thinking it would reduce the processing time. Till date, I have not seen any share or any profit on the grounds that we're not making much of it.

We have not signed any papers that can prove that I'm a partner in the business, but I have made 2 payments (about 90% of my total investment) through a bank transfer to the company's bank account.

To sell my share, would it suffice if I get him to sign on a paper that we are 50/50 partners and I contributed with X amount?

Should it be done at a notary and have it legally attested? Or should I have him sign a paper that I gave him an X amount as a loan?

Any other suggestions