Can't connect to Chromecast using one phone and hotspot

[NeedySumBtch420]

I'm not sure what gen my Chromecast is  it I'm trying to connect to my Chromecast using only one phone and hotspot I have downloaded the Google home app and I know it's possible to connect to Chromecast using one phone and hotspot I have done it before but my phone broke so I got another phone same model exact same phone but I can't remember how I did it everyone is telling me I need a second phone which is not true I have done it with one phone 

[Byteguy]

I am sorry, not all phones support that ability.

Most phones can't make a network (hotpsot) and then also be ON the network (to control the Chromecast).

That is why we suggest that you always use two devices; one to make the network and one to control the network.

Yes, some phones can do this.  But it's more common that they cannot.