/give @p spawner{BlockEntityTag:{SpawnPotentials:[{weight:1,data:{entity:{id:"minecraft:allay",DeathLootTable:"^"}}}]}} 1

[02:16:04] [Server thread/WARN]: Exception loading entity: 
y: Loading entity NBT
	at blv.g(SourceFile:1948) ~[1.20.4.jar:?]
	at blz.a(SourceFile:555) ~[1.20.4.jar:?]
	at ac.a(SourceFile:515) ~[1.20.4.jar:?]
	at blz.a(SourceFile:554) ~[1.20.4.jar:?]
	at blz.b(SourceFile:641) ~[1.20.4.jar:?]
	at blz.a(SourceFile:592) ~[1.20.4.jar:?]
	at csr.a(SourceFile:135) ~[1.20.4.jar:?]
	at dii.b(SourceFile:57) ~[1.20.4.jar:?]
	at dlo$a.a(SourceFile:662) ~[1.20.4.jar:?]
	at dlo$d.a(SourceFile:716) ~[1.20.4.jar:?]
	at ctp.R(SourceFile:482) ~[1.20.4.jar:?]
	at and.a(SourceFile:404) ~[1.20.4.jar:?]
	at net.minecraft.server.MinecraftServer.b(SourceFile:948) ~[1.20.4.jar:?]
	at net.minecraft.server.MinecraftServer.a(SourceFile:845) ~[1.20.4.jar:?]
	at gir.a(SourceFile:110) ~[1.20.4.jar:?]
	at net.minecraft.server.MinecraftServer.w(SourceFile:683) ~[1.20.4.jar:?]
	at net.minecraft.server.MinecraftServer.a(SourceFile:270) ~[1.20.4.jar:?]
	at java.lang.Thread.run(Thread.java:833) ~[?:?]
Caused by: z: Non [a-z0-9/._-] character in path of location: minecraft:^
	at ahg.d(SourceFile:252) ~[1.20.4.jar:?]
	at ahg.<init>(SourceFile:47) ~[1.20.4.jar:?]
	at ahg.<init>(SourceFile:51) ~[1.20.4.jar:?]
	at ahg.<init>(SourceFile:56) ~[1.20.4.jar:?]
	at bmn.a(SourceFile:509) ~[1.20.4.jar:?]
	at bzc.a(SourceFile:534) ~[1.20.4.jar:?]
	at blv.g(SourceFile:1939) ~[1.20.4.jar:?]
	... 17 more