Let me preface by saying that I do not know about Samsung fridge connectivity, however, I do have other brand connected appliances. Every connected appliance I have had pretty much the same connection procedure, so you can try this. connected appliances usually have their own internal wi-fi network, so to connect it to your home network, you need to connect your phone to that wi-fi network (should be some variation of the mfr or model name with some numbers maybe). Most appliances need to be connected to the 2.4 ghz band of dual band modems and many ISPs bridge the two. Most appliances are not smart enough to figure out which band they belong on, so you may have to go into your modem settings and unbridge them. If the refrigerator has an app of its own, you should connect open that, as it will usually walk you through the steps - instructions should also be in the manual. After connecting to the fridge's wi-fi, you should be asked to connect to your home network. At that point, you should enter the password for your home network and it will transfer over to that network. You can then disconnect your phone from that network and re-connect to your home network. These are abbreviated, generalized instructions, but you get the idea. I am almost certain all appliances either have their own app or, in the case of Samsung, can be configured in Smart Things. Sometimes I think connected devices are more trouble than they are worth with connecting them to their own app, Alexa, Smart Things and anything else that will control the device.
I strongly suggest looking for the instructions in the manual, downloading the app if there is one and following the instructions (which sound more complicated than they are).
