Looks like there may be a bit of confusion on the standards.
ISO 13485 is a quality system standard for which you can apply and get your quality system registered. It does not speak directly to software. It does call out 14971 for risk management so there's an expectation that your quality system incorporate a risk management process. So 13485 is at the company level and your quality system would likely incorporate the 62304 aspects as part of your quality system approach.
62304 is strictly a software development lifecycle standard. As far as I know, a company cannot get "licensed" for it. 62304 is a recognized consensus standard in the US and a harmonized standard in the EU so compliance to it will give you a presumption of conformity to the relevant requirements for products in those jurisdictions. It also calls out 14971 so risk management for software is necessary. 14971 does not require
FMEA for risk management (of software or anything else); however, that's probably the most common approach - although it's generally a separate FMEA (a software-specific FMEA). 62304 does call out some specific aspects to consider as part of your (software) risk management. (And if you have an electro-mechanical system that gets assessed for safety under 60601-1 and your software is considered "PEMS" [Programmable Electronic Medical Systems] then there are some additional considerations for software risk management.)
I don't see any particular difficulty in applying FMEA concepts to software. As noted above, there are drivers (62304 and 60601-1) that you should consider in your FMEA.
As your attachment points out, 62366 should also be considered if your software provides a user interface. That standard also calls out 14971 and has expectations for identifying risks associated with use (generally incorporated in a use-specific FMEA).
You should have a comprehensive risk management process that incorporates approaches to risk management for software and use as well as for design (
DFMEA) and manufacturing (
PFMEA).
On another note, pretty much everywhere you would want to market is requiring a cybersecurity assessment. There are standards and guidance docs for this as well and you should absolutely address this to ensure successful regulatory clearance.