Not sure if they are still making them, but it's pretty awesome.
I bought mine for around $200, but apparently they're up to almost $400 on amazon.
I'll just link you to this guy's solution:
https://adrian.siemieniak.net/portal/makita-18v-lxt-portable-power-station-howto/
Or just buy the DeWalt power station:
https://www.amazon.com/DEWALT-DCB1800B-FLEXVOLT-Portable-Station/dp/B01H41SDGU
Yeah, there are, but they aren't cheap. You are probably better off buying a battery powered lawnmower instead.
This is basically a full 20a circuit, and can power anything you can run off a standard home edison plug: https://www.lowes.com/pd/EGO-NEXUS-POWER-STATION-KIT-2X7-5AH/1003130756
If you have a bunch of wireless tools and batteries already, most tool companies have a version of this, too. For example, Dewalt has one for $500 *WITHOUT* batteries: https://www.amazon.com/DEWALT-DCB1800B-FLEXVOLT-Portable-Station/dp/B01H41SDGU/ref=asc_df_B01H41SDGU/
But that said, you can also get their 20v lawn mower for only $400. It's going to be more efficient running off a DC motor, rather than an AC motor with power going through an inverter. I think last time I looked inverting you lose 20% power on DC to AC conversion alone. https://www.homedepot.com/p/DEWALT-21-5-in-20-Volt-MAX-Lithium-Ion-Cordless-Battery-Walk-Behind-Push-Mower-DCMWP233U2/314269627
Note that I haven't actually price/value compared the above items, they are just some quick searches. If you go this route, make sure that the continuous run wattage is enough to run the tool in question. 1800 watts is enough for a 15 amp tool, which will probably run anything you have.
Maybe you don't need power? You could use something like https://www.amazon.com/DEWALT-DCB1800B-Portable-Power-Station/dp/B01H41SDGU and LED work lights
So they do, though it is $350. I'm imagining just how useful that could be though, you could take the thing camping or out on a picnic or out on the deck even. An extension cord is certainly cheaper though, I will admit. And while portable, it would be like 30lb with batteries.
I've something similar to this (but not this... can't find what I used) to power PAs for wedding ceremonies and parade floats.
https://www.amazon.ca/DEWALT-DCB1800B-Flexvolt-Portable-Station/dp/B01H41SDGU
https://www.amazon.com/Xantrex-802-1500-XPower-Portable-Powerpack/dp/B00005RHQQ
Could also check your local rental houses.