When you submit a transaction on Binance Smart Chain, Polygon Chain or even Ethereum, your gas price is a bid to the network to process your transaction sooner. Which means that a higher gas results in a faster transaction.
If you submit a transaction with a low gas price, it may be possible you can find your transaction taking a very long time to process! This happens also in times of massive congestion, when the "normal" gas price is too low to carry a transaction through.
In this case, you can try one of the options below:
Wait until the network is willing to process transactions at this price;
If you haven't done so already, click that button that says Speed Up (1). This will let you re-submit the same transaction, but with a higher gas fee that should allow the transaction to be processed faster.
If the previous options does not work and if you haven't done this already: cancel the transaction by simply selecting Cancel (2). Please note, a cancellation can only be attempted if the transaction is still pending on the network.
For more information, see the official Metamask documentation.