Ann: Notification of MLSOB Option Expiry, page-8

Just to give more context as I can feel for you that its something new -

As thon0915 said, 3 things you can do

a) exercise the option at the exercise price prior to expiry
Here is the notice:
Metals Australia Limited (“MLS” or the “Company”) advises that the attached letter has been sent
to registered holders of listed options (ASX: MLSOB) (Options) which are exercisable at $0.07 on
or before 5pm (WST) on 1 June 2022 (Expiry Date).
Official quotation of the Listed Options will cease at the close of trading on 26 May 2022, being four
business days before the Expiry Date.
Holders of the Options can exercise all or part of their Options prior to the Expiry Date by providing
the Company with a completed written exercise form notice specifying the number of Options being
exercised and a payment of funds for the total exercise price for the number of Options being
exercised.

So you will need to spend 7c to convert. Eg if you have 200,000 options, you will require $14k. Once you convert, they will become shares. At current price, you can sell them for 9.1c = $18.2k. So a gain of $4.2k at current prices. Of course you should have $14k money to convert and also hope/expect that MLS shares will be above 7c - chances are very good that it will remain above 7c, but its your money and anything can happen. If the MLS shares rise to say 11c, you may gain $8k.
.

b) sell the option prior to expiry
Here if you sell currently in market, last sell was on 1.3c. The buy is on 1.2c as of today. If you sell 200k options, you get $2.4k. You don't have to do anything. The price may further increase in next few days, so there is a chance you could sell higher than 1.2c - but again there is no guarantee.
.

c) let the option lapse (the options will become worthless once they expire)
If you do this, you will not have to pay anything, but you may lose potential gains as doing either a or b. If you don't intend to convert, eg you don't have money to convert, in your place I would sell the options so I get something. If you let it lapse, you get nothing