Susan,
That's a spade connector, and you need to size it for the studded connections on the back of the power supply. A photo I'm looking at leads me to believe the studs are either 1/4" or 5/16" in diameter.
Equally important is the proper size crimp-on connector for the gauge of wire you will use. This is a 25 amp supply, and is quite capable of frying wire that is too small. The connectors in your pic are color coded for 22-18 ga wire, WAY too small for this amount of current. Here is a color code chart for the connectors:
Screenshot at 2043_02-14.png
Wire gauge is determined by considering how long the length of the wire run is and the amount of current (amps) it can safely handle. For a modest load, say 8-10 amps, and a 12' run of wire, 10 ga is suggested, but you could probably use 12 ga, or even 14 ga, but certainly no smaller.
A thermal wire gauge chart can be found here:
https://dcthermal.com/wire-guidecharts/
It is very conservative on current capacity... it will point you to very large wire for the application.
I ran a 5 watt HT, TNC, and cooling fan on 14ga wire (15' long) for years without an issue. I used the Blue color coded connectors... the Yellow ones were a bit large for 14ga wire.
Hope that helps!