Js string interception?

this is a recording link, how to intercept 6922, but the string length may be different, and the number of digits is not certain, how to intercept
/usr/files/20180523/a33e1377-7d70-4213-b59f-4d51b1e673c5aef0eaf9d18472d.durationTime=6922.mp3
Mar.13,2021

is guaranteed to be a number. Mp3 means
regular

.
/(\d+)\.mp3$/

clipboard.png


str.match(/\d+(?=\.mp3\b)/ig);
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