Biden's signature matches his signature available on his website.
When he looked a couple of days, some executive orders had been published, and he noticed that Biden's signatures looked forged.
He further states that Biden was probably embarrassed by his shaky signature since he has mid to late-stage dementia and that his wife, Jill Biden, signs for him on legal documents.
In the video, the narrator also claims that Jill Biden is his "handler" or "minder".
RedPill78 is a major QAnon influencer known for spreading disinformation and misinformation and is known for making wild claims without evidence. Twitter suspended RedPill78's account in October 2020. The claims made in this video are also not true.
In a video posted on January 20, Biden's first day in office, we can see Biden signing an executive order. His hand is not shaking, and Jill Biden is not there to help Biden sign any executive orders. Moreover, all of Biden's executive orders, which he has signed at the time of writing, are available on the Federal Register, and the signatures match perfectly with his signature available on his campaign website.
Logically has previously debunked the claim that Biden has dementia, and Biden's medical records released during the 2020 presidential campaigns (December 2019) reveal that he is healthy and fit to execute the duties as President of the United States. It mentioned that Biden is taking medication only for acid reflux, cholesterol, and seasonal allergies.