It all depends on the size of the crack. If this is a microcrack, then you can fix the defect yourself. Repair of wider cracks is best left to a specialist. In this case, professional material and special tools are used. If you do not know how to fix the problem at all, call the wizard and save your time. Just in case, I will share a link to an article about crack repair https://www.pomwaterproofing.ca/how-to-fix-foundation-cracks-from-outside/ . Here is information on how to fix small cracks that occur.