My Mac randomly shut down and appeared to be off of battery

My Mac just randomly shutting down and it showed on the screen that the battery is low and wouldn’t restart. However, I am pretty sure that my Mac is enough charged, because I literately just used my Mac for 1 hour after it had been charged for whole night. The last time my Mac shut down and I plugged in charger, it reopened it and appeared to have 40% of its battery

what could be the possible issue for this case? This really impact my usage because I am unable to use my computer in class.