From the Brief we can see it is a python package. Downloading it and importing it gives the cipher text:
$ pip install spentalkux
$ python
>>> import spentulkux
Hello.
Can I help you?
Oh, you're looking for something to do with *that*.
My creator left this behind but, I wonder what the key is? I don't know, but if I did I would say it's about 10 characters.
Enjoy this.
Ztpyh, Iq iir'jt vrtdtxa qzxw lhu'go gxfpkrw tz pckv bc ybtevy... *ffiieyano*. New cikm sekab gu xux cskfiwckr bs zfyo si lgmpd://zupltfvg.czw/lxo/QGvM0sa6
Goodbye now.
That's your cue to leave, bro
Exit stage left, pal
OFF YOU POP.
You know what I haven't got time for this
Forking and executing rm -rf.
The code can be deciphered with a Vigenere cipher using the key: spentalkux
Then visit pastebin "https://pastebin.com/BCiT0sp6" and decode hex that forms an image
The image says to look back into the past which means the previous release of spentalkux
pip install spentalkux==0.9
It then gives another code
JA2HGSKBJI4DSZ2WGRAS6KZRLJKVEYKFJFAWSOCTNNTFCKZRF5HTGZRXJV2EKQTGJVTXUOLSIMXWI2KYNVEUCNLIKN5HK3RTJBHGIQTCM5RHIVSQGJ3C6MRLJRXXOTJYGM3XORSIJN4FUYTNIU4XAULGONGE6YLJJRAUYODLOZEWWNCNIJWWCMJXOVTEQULCJFFEGWDPK5HFUWSLI5IFOQRVKFWGU5SYJF2VQT3NNUYFGZ2MNF4EU5ZYJBJEGOCUMJWXUN3YGVSUS43QPFYGCWSIKNLWE2RYMNAWQZDKNRUTEV2VNNJDC43WGJSFU3LXLBUFU3CENZEWGQ3MGBDXS4SGLA3GMS3LIJCUEVCCONYSWOLVLEZEKY3VM4ZFEZRQPB2GCSTMJZSFSSTVPBVFAOLLMNSDCTCPK4XWMUKYORRDC43EGNTFGVCHLBDFI6BTKVVGMR2GPA3HKSSHNJSUSQKBIE
The rest can be done in cyberchef
From Base32 -> From Base64 -> Gunzip -> From Binary -> From Binary -> From Hex -> From Base85
ractf{My5t3r10u5_1nt3rf4c3?}