The whole point of an NVR is that it’s not stamped. You get it before you go and then you never need a visa or a stamp regardless of whether you’ve been there or not.
Bangladesh haven’t commented on whether or not she’s been there before, nor has she, her family, her lawyer or the UK government.
“Shamima Begum is not a Bangladeshi citizen. She is a British citizen by birth and has never applied for dual nationality with Bangladesh,” Masudur Rahman, the Director General (external publicity) of the Foreign Ministry of Bangladesh, said in a press release tonight.
“It may also be mentioned that she never visited Bangladesh in the past despite her parental lineage. So, there is no question of her being allowed to enter into Bangladesh,” the press release said.
“The Government of Bangladesh is deeply concerned that she has been erroneously identified as a holder of dual citizenship shared with Bangladesh alongside her birthplace, the United Kingdom,” it added.
www.thedailystar.net/country/news/shamima-wont-be-allowed-enter-bangladesh-foreign-ministry-1705225
Of course, the citizenship part is contentious but they have said she's not been there and surely would know so if she's had to apply for the NVR as she'd be on the system having applied for it.