Wikipedia page about this book: https://en.wikipedia.org/wiki/The_Book_of_the_Thousand_Nights_and_a_Night

Here is the listing of titles for the entire series, which span multiple digitization efforts:

Volume 1: #3435, #51252
Volume 2: #3436, #51775
Volume 3: #3437, #52564
Volume 4: #3438, #53254
Volume 5: #3439, #54257
Volume 6: #3440, #54525
Volume 7: #3441, #54778
Volume 8: #3442, #55091
Volume 9: #3443, #55587
Volume 10: #3444, #58360
Supplement Volume 1: #3445, #59156
Supplement Volume 2: #3446, #59953
Supplement Volume 3: #3447, #60889 (part 1), #61974 (part 2)
Supplement Volume 4: #3448, #62140
Supplement Volume 5: #3449, #63266
Supplement Volume 6: #3450, #64384

Release date is 2021-01-25

Richard Tonsing, Richard Hulse, and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive)

"Supplemental Nights to the Book of the Thousand and One Nights — Volume 6" by Richard Francis Burton is part of a translation series published between 1886-1888. This volume continues Burton's ambitious project of rendering the complete Arabian Nights into English without censorship. Burton's work includes extensive notes exploring Middle Eastern culture and customs, particularly sexual themes that scandalized Victorian society. Published privately to avoid obscenity laws, these supplemental volumes expanded his original ten-volume translation with additional tales from the Islamic Golden Age's legendary story collection. (This is an automatically generated summary.)

Original publication data not identified