Please see the steps below for clearing the hidden HTML text:
1. Open the Letter Template in the Editor and copy the Letter Text
.png?Policy=eyJTdGF0ZW1lbnQiOlt7IlJlc291cmNlIjoiaHR0cHM6Ly9kemY4dnF2MjRlcWhnLmNsb3VkZnJvbnQubmV0L3VzZXJmaWxlcy8xMTEyOC8xNDIwNS9ja2ZpbmRlci9pbWFnZXMvMSgxMTcpLnBuZyIsIkNvbmRpdGlvbiI6eyJEYXRlTGVzc1RoYW4iOnsiQVdTOkVwb2NoVGltZSI6MTc3NjQxNzk5OH19fV19&Signature=GfXF179i40JxNMgehX6Vv62RYvHZ~V~6nWdXuYsa4RUaLfkfOmq836WpiWYswt9vP8nnoiMNtLFpby9mL7FIdxDNuiJbqhixad4N95hVeve8Eqo5TQH01Hs4KaPdt0soda4oPvzr980vasOYcuP5Q79oVbcuP7jvOFsEe-7sle8~6dGg9V94vwUJkj579c6cU9GwasGIlP0epcvbxJpMKUPaHhbwpJb8kKSgcbeAcVZMoqKcNyd64rLNcb4DbqNgW3WVJG4sK-WSDZCKHjXr~iI0UXJRBaCelN~nvU88HAmAC9gkn-mUqWBuTQ3qI2yjAGemvRhLwBxxPPM7OiCleg__&Key-Pair-Id=K2TK3EG287XSFC)
2. On your web browser go to https://html-online.com/
3. Paste the letter text into the left side HTML, then click on Clean
.png?Policy=eyJTdGF0ZW1lbnQiOlt7IlJlc291cmNlIjoiaHR0cHM6Ly9kemY4dnF2MjRlcWhnLmNsb3VkZnJvbnQubmV0L3VzZXJmaWxlcy8xMTEyOC8xNDIwNS9ja2ZpbmRlci9pbWFnZXMvMig2MikucG5nIiwiQ29uZGl0aW9uIjp7IkRhdGVMZXNzVGhhbiI6eyJBV1M6RXBvY2hUaW1lIjoxNzc2NDE3OTk4fX19XX0_&Signature=SSZiZrOMVcsD2nyfqVPo75UAydG1oTnCSznRHIME2EJqNQ3BeuUXP-b2t3wtNC2MxG1JrGGewnQTIK6z9L8ewJfYFHRQf5VIkzYqdHWV4voyBqc51piy2Utki5EptS8ypYEjOPBRn478hfsBAhMATzCQDzs~4cnLjw~nXJhYzqA~wI7haPIIcIryttWNIJvOUSPob20wxAiK~3MvsucAp-KfX~tYCwa4kAMP979SAFd9SFz60~xSDKptYMTu6E16LcrxrrFiAi9BUCjcRfSvyR~F0yJ7fUMLSGFxzy7KyIIOST9OPv2lH1Jut0SKwOS~ylviA-Y5U~fPOrU4u7o5Uw__&Key-Pair-Id=K2TK3EG287XSFC)
4. Copy the HTML from the right side after the HTML has been cleaned
.png?Policy=eyJTdGF0ZW1lbnQiOlt7IlJlc291cmNlIjoiaHR0cHM6Ly9kemY4dnF2MjRlcWhnLmNsb3VkZnJvbnQubmV0L3VzZXJmaWxlcy8xMTEyOC8xNDIwNS9ja2ZpbmRlci9pbWFnZXMvMygzMykucG5nIiwiQ29uZGl0aW9uIjp7IkRhdGVMZXNzVGhhbiI6eyJBV1M6RXBvY2hUaW1lIjoxNzc2NDE3OTk4fX19XX0_&Signature=RlLASj~nfUjgBbnnRTAWD4ahCsKl38KEGEFC6AN3vtOrFlet8CWLAd8ZMzgKTFyg1jgfp98TWCSK0KRoWvNPW8j0-krGxj9B0LYhzvfd4KVgb~0Mg2D-udCehf2ImERGtu1vVQnm-Ha3ZaaS3sQs02DNpBGSX1D4v2QjWlGEQ5sBkzsGcYmxpJz18fQsBY~jxWL6xUlmjHbATMww-QKkpdeEA5aSilEFWeue3QhKghIdmimcfLJaaFyiFvSvW6aCRP6xzU34nP7T0P1COeo2iOsewfq3x0RQpTafaECuMA4RY06ROqnI~LjYolR~CqyKIWOBDfEfNKU5t-bqMaEELw__&Key-Pair-Id=K2TK3EG287XSFC)
5. Paste the HTML Text into the HTML Source Editor in Agentbox as per the steps below. Click update once added and then preview.
.png?Policy=eyJTdGF0ZW1lbnQiOlt7IlJlc291cmNlIjoiaHR0cHM6Ly9kemY4dnF2MjRlcWhnLmNsb3VkZnJvbnQubmV0L3VzZXJmaWxlcy8xMTEyOC8xNDIwNS9ja2ZpbmRlci9pbWFnZXMvNCgxMSkucG5nIiwiQ29uZGl0aW9uIjp7IkRhdGVMZXNzVGhhbiI6eyJBV1M6RXBvY2hUaW1lIjoxNzc2NDE3OTk4fX19XX0_&Signature=r1nF2E61BgpOl63eTDQ5mT-n9k5HQUngvpn-TCBeE1NcESfaQOxMUIYiVHg-OUPNntQOa~QB6W1QlF4~6P7GG0dURDF7iXBktwJ6JWWVShcT2WNaA2oZc~zJKXCQp31rtUAz0z2KOXcwfR4x~7-JwZ-LNOYQiTjewYuthMMgjtp1VUygxlLhs~yWkqPpQKggo5hLvwk-Y36WP5CZ0Fo4yFBrSQbN-DtmOiIluqiubonvvWwKMgerxNeWC2wyZIK06yjAefdlJRKG0etdHCmQFw0V6428elUS3E2X3hJgv6mm1BuhMb7OO3dO52RXlf6mRbFavoHmitnVz~08mQQHnQ__&Key-Pair-Id=K2TK3EG287XSFC)