Who used phrase keep calm and carry on to help people who stutter?

The phrase "Keep Calm and Carry On" was popularized by the British government during World War II as a morale-boosting slogan. However, it has also been embraced by various groups, including those who stutter. Speech therapists and advocacy organizations have used the phrase to encourage individuals who stutter to remain composed and persistent in their communication efforts, promoting resilience and confidence in overcoming speech challenges.