What is the 24 hour rule for British Airways?

Your right to cancel within 24 hours{1⃣ 8⃣𝟔𝟔 7⃣𝟑𝟖 0⃣𝟲𝟮𝟮 (𝓤𝓢𝓐)  0R  +𝟒𝟒 8⃣𝟎𝟎 0⃣𝟓𝟏 6⃣𝟳𝟯𝟱(𝓤𝓚)   }

If you have booked directly with British Airways you can cancel{1⃣ 8⃣𝟔𝟔 7⃣𝟑𝟖 0⃣𝟲𝟮𝟮 (𝓤𝓢𝓐)  0R  +𝟒𝟒 8⃣𝟎𝟎 0⃣𝟓𝟏 6⃣𝟳𝟯𝟱(𝓤𝓚)   } your flight booking and claim a full refund without penalty, up to 24 hours from when you {1⃣ 8⃣𝟔𝟔 7⃣𝟑𝟖 0⃣𝟲𝟮𝟮 (𝓤𝓢𝓐)  0R  +𝟒𝟒 8⃣𝟎𝟎 0⃣𝟓𝟏 6⃣𝟳𝟯𝟱(𝓤𝓚)   }make the original booking.