Menu > Print Menu > Save
There used to be an option to Print or Save files. This would be helpful when a website contains information that is larger than the area that a screen capture can gather and needs to be saved on the device.
See https://github.com/mozilla-mobile/fenix/issues/3709, https://github.com/mozilla-mobile/fenix/issues/10217, https://github.com/mozilla-mobile/fenix/issues/219
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See https://github.com/mozilla-mobile/fenix/issues/3709, https://github.com/mozilla-mobile/fenix/issues/10217, https://github.com/mozilla-mobile/fenix/issues/219