Who can provide the following runtime curve drawing tutorial video url?

[Everynone]

Depends on what you mean by curve. Spline mesh components can do 3D curves, you could use particles. You could take advantage of this wicked plugin:

How can I draw multiple lines in UMG

Unreal default “DrawLine” api has inconvenient points for developers: Lines can not be previewed and edited in UMG editor. Hard to edit complex lines. Can not draw splines. Can not set a brush for the line geometry. Can not be used as a rail for other widgets. Maybe you can try the “UMGSpline” plugin to solve your problems: UMGSpline in Code Plugins - UE Marketplace