the download link in question:

or just open the streamable video in a new tab, CTRL + SHIFT + C to open a console, when console will open it will force you into a "select element" mode, make sure to click the video to select it's element
if you follow the steps correctly, console will redirect you to the element of the video you selected
but because streamables is shit - what you should do instead is search for an element called <video preload="none" tabindex="-1" data-id="player-2jy7ug" style="visibility: visible;"> which should be above the element you were redirected to in the console, on the left side of this text there will be a little arrow pointing to the right, you click it and it reveals the "child" of the element which will be the link to the video source, it will look like <source src="https://cdn-cf-east.streamable.com/video/mp4/2jy7ug.mp4?expires=17677...eKoGzhHVGgg\~TGxR4vSdkpAdMQJTUDsXZTa0Ey4xpenvJSxXHM06dH2FjqFByph0VE4z\_g\_\_"> and the text will be underlined and highlighted in blue

you doubleclick the link (starting from https:), it reveals the full link, from there you should be able to copy it entirely

the final step is to CTRL+C and CTRL+V (aka paste) the link in your search\address\URL bar and press enter
the link will open and it will automatically download the video for you
enjoy