In the normal physiological state of the human body, there are coagulation systems and fibrinolysis systems in the blood that resist each other. These two systems are in the process of dynamic equilibrium, which enables the blood to have a potential coagulation function and ensures that the blood is always in a fluid state. However, under the influence of certain factors (such as vascular endothelial injury, abnormal activation of the coagulation system, changes in blood flow, etc.), this dynamic balance is broken, so that blood coagulation or some formed components in the blood adhere to each other, the above process leads to the formation of thrombus.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6485664/

What Are Factor Xa Inhibitors?
They’re in a class of blood thinners called direct oral anticoagulants, or DOACs. They work by targeting tiny molecules called factor Xa, a substance that helps the platelets, cells, and proteins in your blood stick together, or clot.

Factor Xa inhibitors block the final step needed to make thrombin. That’s an enzyme in your blood that turns something called fibrinogen into fibrin, which helps you close up wounds. People whose bodies make a lot of thrombin seem to be more likely to have recurrent DVT or PE.

You can get factor Xa inhibitors with a prescription from your doctor.

https://www.webmd.com/dvt/factor-xa-inhibitors-for-dvt

Prothrombin is transformed into thrombin by a clotting factor known as factor X or prothrombinase; thrombin then acts to transform fibrinogen, also present in plasma, into fibrin, which, in combination with platelets from the blood, forms a clot (a process called coagulation). Under normal circumstances, prothrombin is changed into thrombin only when injury occurs to the tissues or circulatory system or both; therefore, fibrin and blood clots are not formed except in response to bleeding.

https://www.britannica.com/science/prothrombin

I've just found this :-)

'These agents prevent factor Xa from cleaving prothrombin to form thrombin and bind directly to factor Xa, rather than enhancing the activity of antithrombin.'

https://www.uspharmacist.com/article/assessing-novel-oral-an...

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Note added at 1 hr (2023-11-10 10:45:50 GMT) Post-grading
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Glad to be of help :-) I hope you didn't waste too much time trying to decipher the source text.