qif to qfx conversion represents export between two types of Quicken formats, both used for interchange/exchange purposes, but perhaps from different versions of the accounting software. Except for Quicken itself, plenty of 3rd party software apps supports its formats, so it should not be difficult to find one, that can do this export for you. You might even find some online (webpage based) converters for this.
Updated: August 29, 2023