[TexasGator]

"after the production of the hydrogen"

Negligible amount. E=MC²

Much less mass is converted in the chemical reaction.

[adorno]

Negligible amount. E=MC2

I don't believe that equation is applicable to electrolysis.

Much less mass is converted in the chemical reaction.

The question is still...

How much more net energy will be produced that will be greater than the expended energy to produce the hydrogen and then to fuse the hydrogen.

IOW, is...

net gained fusion energy > (energy to produce hydrogen + energy to fuse the hydrogen)

If the netGainedFE not greater than spent energy for Electrolysis + spent energy for fusion ignition

then...

Not worth it

Also consider that there are personnel charges and equipment charges and building charges, and likely many others.