What is it you mean by lost passwords? In regards websites or?
There is no spell for this.
If you mean lost website passwords your best bet is a password recovery or change using the email you used to sign up to the website with.
Let us know if this is what you mean to ask about.
Your message is not very clear.
I know this is going to sound like terrible advice, but remembering is the likeliest option.
Relaxing helps with memory. You may also want to consider trying to remember things you enjoyed when you started your account.
Also in general, don't answer this here but to yourself, what do your passwords generally look like?
A spell may not be the best option, but it may help you relax and help remember. Piece or happiness spells can be great for this.
Generally when you sign into a website it gives you an option to use if you have forgotten your password. You might check to see whether this is possible to get you into your instragram account.