name can only contain URL-friendly characters

I was trying to install package.json with npm init to install bootstrap in my folder but i am getting the error.

npm install bootstrap@4.0.0-alpha.6 --save

I am new to this i can't exactly figure what i am doing wrong. I was following a tutorial whose link i'll attach along with screenshot of my console.

this the tutorial link

I was getting the same problem but I changed package-name first name was like:

My Folder Name

I changed it to

my-folder-name

with no spaces & no capital letters. It solved the problem for me. Happy coding