If the aglet (plastic bit around the tip of a shoelace) falls off and you can't lace your shoes without them, you can tightly wrap thread around them and seal it with

Use heat shrink tubing to repair lost aglets. : r/lifehacks

How do I repair the plastic caps at the end of shoe laces? : r/myog

Aglets For Shoelaces

Repairing your Shoelaces with Flossand Fire!

Applying super glue inside the plastic tip compared to glue alone or using a PVC tip alone is double coverage resulting in a stronger, longer lasting

Shoelace Tips Plastic Lace Ends Shoe Lace Repair 7 Colors 5 Sizes~~~~~~~id4663

How to fix frayed shoe lace tips to look like factory lace tips

Shoelace Aglet/Tip Repair and Replacement [5 Methods in 5 Easy Steps] - Help Shoe

Quick, Cheap & Easy Fix for Frayed Laces / Broken Aglets : 6 Steps (with Pictures) - Instructables

Aglets For Shoelaces

How to shorten your shoe laces and make aglets. : r/howto