Why does 'axt' and 'aaa' not work in Radare 2?

Question

Here's everything I typed:(I followed this tutorial: https://crackmes.one/static/solution/5b51b18833c5d41c0b8ae543.zip)

xeus@Xeus:~/Downloads/Crackmes$ r2 crackMe1.bin
[0x000008a0]> aaa
[0x000008a0]> fs strings
[0x000008a0]> f
0x000008a0 256 entry0
0x00202048 4 str.H
0x00000b9e 13 str.Badpassword
0x00000b90 14 str.Goodpassword
0x00000b85 11 str.Password
[0x000008a0]> axt str.Password:
XXX: This command conflicts with 'ar'
Usage: ax[-cCd?] [src] [dst]
 axc sym.main+0x38 sym.printf   ; add code ref
 axC sym.main sym.puts          ; add call ref
 axd sym.main str.helloworld    ; add data ref
 ax- sym.main str.helloworld    ; remove reference
[0x000008a0]>