You’ll be doing this every time you acknowledge their strengths, the brave things they do, their effort when they do difficult things, and their tiny shuffles or big leaps towards braveness.
This isn’t always easy. Their anxiety will trigger ours - when our children feel unsafe, often so will we. So, we have to hang on strong to the truth of it all - that we know they can do this. If you feel yourself believing in their anxiety more than their braveness, remind yourself that they will believe in themselves when you do. Then, breathe, find calm and let your courage lead theirs.