PS C:\Users\user> $activationKey = Get-Content -Path "C:\Users\user\Desktop\activation_key.txt"  -Raw

PS C:\Users\user> $activationKey
GUFN1GBB9V6MUYBSJ6ZT5OUB2JK2AOJM2WQ2
I0I839GIRORFZN5SDG849LP06MJH6PG5E8X5
CW3ZRW0HGI6JER5D7FB0U72UBKRN58YSDZAJ
CEICRBB8KHHE3BA5HB71KZOV64V8BD8V36TD
5GAUMMGPTAP96Q6LWLRF2ZZ7VE8HZ8C1DJ6V
D37UB727VT6WXE4QSNAK2N2LZY3KVGX2TCE8
7CHULP28RS4DYCD3X1JCLB90RLHWHG44XJH6

PS C:\Users\user> $activationKey.GetType()

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     String                                   System.Object