Hi!
To reset the BIOS password you need to remove the coin-cell battery and short out its contact points. This should reset the password.
We don't have a guide on your specific model, but I came across [https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/thinkpad_11e_yoga_11e_ug_en.pdf|this] user manual that explains the procedure of replacing the battery. Scroll to page 108. Good luck.