What are my rights as a employee with a temporary contract and as an non EU national?

On March 1st 2021, I started working at a company on a temporary contract (1year duration). Two days ago, in the pre-text of my mid-year review, my manager told me that they would like to cut short the contract and let me go. An agreement was sent to me to sign my Monday and it states that i will get 3months salary along with a transition fee. This decision is sudden and there was no previous discussions that implied that this might happen. It also poses implications on my visa status currently. As a non-EU national, I would like to know what my power in this situation is and also get some advice on what the right financial compensation I can ask in this situation.