VFS Global Session Expired Or Invalid Error Blocks US Visa Application

I am trying to schedule a USA visa appointment through usvisascheduling.com and to pay the visa application fee via the “Click here to pay with cash” option, which redirects me to the VFS Global page. For the last 6 hours, every time I try to proceed on the VFS Global side, I receive a “Session Expired or Invalid” error, which completely blocks me from continuing the process. This is my first time using this system. I have already completed my DS-160 and all the prior steps on usvisascheduling.com and I am now stuck only at the payment stage. Because of this recurring error on the VFS Global page, I have not been able to pay anything at all for this visa process and therefore cannot move forward with booking an appointment. I also attempted to use the VFS Global contact page for support, but that page also returns an error and does not allow me to submit a request. I kindly request that this technical problem with the “Session Expired or Invalid” error be urgently investigated and resolved, or that I be provided with an alternative, working method to pay the visa application fee and proceed with the appointment scheduling without further delay. This issue is time‑sensitive for me, and I am unable to advance my application solely due to this technical malfunction on your systems.