Dear 亚权 白,
the datasheet for the FS26 is confidential. It can be downloaded only with a valid NDA (Non Disclosure Agreement) with NXP.
If you have a valid NDA with NXP, you should be able to download the FS26 from the FS26 product page, under the Secure section.

If you haven't the NDA yet and you would like to sign one, please create a new ticket here and an NXP representative for NDA matters will help you with the process.
With Best Regards,
Jozef