Its an inlet.
If you don't want the hassle of an interlock or transfer switch, look into something like this Reliance Control Corporation WKPBN30 Portable Generator Through-The-Wall PWR Transfer Kit, EMW3790037 https://www.amazon.com/dp/B0743BQDT4/ref=cm_sw_r_apan_glt_fabc_Z2ST5ETBMNDYKM8E3QQH
You will have to run extension cords to your devices, but it's cheaper
It needs some care in planning but at the end of the day it's no different from running some stuff off a generator in a power outage. 12 gauge cord for heavy loads. A kit like this but with a different source outlet might be wise:
Reliance Control Corporation WKPBN30 Portable Generator Through-The-Wall PWR Transfer Kit, EMW3790037 https://www.amazon.com/dp/B0743BQDT4/ref=cm_sw_r_cp_api_i_piBcEb7NFY6HN
I'm not saying this will suit you but just letting you know it exists.
Reliance Controls - Portable Generator Through the Wall Kit Lowe's
I installed the Reliance "through the wall" kit $110, and have extension cords ready! Figure I can power the refrigerator, microwave, furnace, tv/dvd, lights, etc. Just have to worry about tripping over cords! Will need some red cones in the house. https://smile.amazon.com/Reliance-Control-Corporation-WKPBN30-EMW3790037/dp/B0743BQDT4/ref=sr_1_3?crid=34RLW9QB1CBW5&keywords=reliance+through+the+wall+generator+kit&qid=1670884968&sprefix=reliance+through%2Caps%2C175&sr=8-3
Are you running this at home or at some remote location? The reason I ask is that's an odd list of things to want to run. Usually the list includes a refrigerator.
Anyway, if it's just those items, are located close together and you have a wall to pass through for running your generator outside (which you should do) then you'll need some sort of a passthrough, like this maybe (in lieu of an interlock or transfer switch)>
https://www.amazon.com/Reliance-Control-Corporation-WKPBN30-EMW3790037/dp/B0743BQDT4
Finally, personally I'd opt for the Champion brand instead, such as this item for just over $400.
https://www.amazon.com/Champion-Power-Equipment-100692-Ultralight/dp/B0812PNK3X
Easiest and cheapest.
[Reliance Controls - Portable Generator Through the Wall Kit](https://www.lowes.com/pd/Reliance-Controls-30-Amp-6-Space-Generator-Power-Inlet-Box/1000974678)
[Portable Generator Through the Wall Kit](https://www.homedepot.com/p/Reliance-Controls-Portable-Generator-Through-the-Wall-Kit-WKPBN30/307438017)
[Reliance Controls - Portable Generator Through the Wall Kit](https://www.amazon.com/Reliance-Controls-WKPBN30-Portable-Generator/dp/B0743BQDT4)
[HOW to CONNECT a Portable Generator to a HOUSE with a Transfer Switch?](https://www.chainsawjournal.com/how-to-connect-a-portable-generator-to-a-house/)
[Generator Interlock Kits](https://www.geninterlock.com/)
There's more advanced stuff but really for electricians.
They were linking the Reliance through-the-wall kit. Works great, but usually won't power your furnace. You could install this to your furnace to allow you to toggle the furnace between generator and hardwired.
As others have said - I wouldn't put a dime into your panel unless you are interested in replacing it.
Reliance Control Corporation... https://www.amazon.com/dp/B0743BQDT4?ref=ppx_pop_mob_ap_share
It depends on how cheap you are.
This is the cheapest halfway good system.
Portable Generator Through the Wall Kit
https://www.homedepot.com/p/Reliance-Controls-Portable-Generator-Through-the-Wall-Kit-WKPBN30/307438017
Reliance Controls - Portable Generator Through the Wall Kit
https://www.amazon.com/Reliance-Controls-WKPBN30-Portable-Generator/dp/B0743BQDT4