Since this Qadiyani propaganda is at its peak these days, just for academic integrity it is important to note the following chronology since supporters of Mirza Ghulam Ahmad (MGA) often try to trick unsuspecting Muslims:

1- 1835: MGA is born
2- Up till 1880: MGA is Sunni

3- 1882: MGA declares himself a Mujaddid and starts rubbishing every other Maulvi to position himself leader of the pack.
4- 1883: MGA claims his persona consists of the spirits of multiple people
5- 1884: MGA claims he is receiving revelation directly from God

6- 1891: MGA claims to be Isa (AS)
7- 1894: MGA claims he is the Awaited Mahdi
8- 1899: MGA claims he is deputed with role of prophets
9- 1900: MGA writes a book on his unstinting support to the British Raj
10- 1901: MGA finally claims to be a Prophet in unambiguous terms

When you see Ahmadis quote MGA saying that he believed in the finality of the Prophet (SAW), they are quoting his works from 1880 - 1883. What they will unscrupulously hide from you are his works from 1901 onwards when he categorically and unambiguously claimed to be a Prophet.

Quotes such as these:

"I swear by God in whose hand lies my existence and say that it is He who has reputed me and called me a Prophet and the Messiah." (Haqiqat-ul-Wahi, Appendix, Page 68, Mirza Ghulam Qadiani)

"How can I discard God's revelations which has been coming to me for the last twenty-three years. I believe in this sacred revelation as I believe in the revelations before me." (ibid, Pg. 15)

Furthermore, MGA till his death gives numerous fatawa declaring all Muslims Kaafir

for rejecting him as a Prophet. And it’s not just him, but his Khulafa after him uphold this takfir. Till present day Khalifa Mirza Masroor who also upholds the takfir. Like I said in a previous tweet, Roohani Khazain is a collection of all his works. You can find all this there.