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=eyJTdGF0ZW1lbnQiOlt7IlJlc291cmNlIjoiaHR0cHM6Ly9kemY4dnF2MjRlcWhnLmNsb3VkZnJvbnQubmV0L3VzZXJmaWxlcy8xMTEyOC8xNDIwNS9ja2ZpbmRlci9pbWFnZXMvMSgxMTcpLnBuZyIsIkNvbmRpdGlvbiI6eyJEYXRlTGVzc1RoYW4iOnsiQVdTOkVwb2NoVGltZSI6MTc2NTgzMzY5Mn19fV19&Signature=ee-gOSs1VAllm8Mhi13KTBY4o2PdhlIs3ATpSMthtwinXKHxQHUguPZdTja6~hlcaP6jVY7PG1leBgi5HMYdABINC-Be7smws0hOquKeGgKvcMv4qAA8WDUeT2z~ID~VkhlJT4wl-iu9Pm0yHZ3cpAACKYu8Z8Xcp-hCWru9YIf1s5KSii0H3V38FFFdfSIW0cy~vRuTkaN2yffGIsOLpvByK70Kd~~Y-LHLKWwahZzGdZ10VenbCSbVhY9rxrJRYP7LOzKY97RejlnSydV0hyhnR5VpnY3xGcOIL73hbRdPzHJ962BSTd-0ny1ymOGpX~zdpzGNIGAnvc2lgUVj-g__&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=eyJTdGF0ZW1lbnQiOlt7IlJlc291cmNlIjoiaHR0cHM6Ly9kemY4dnF2MjRlcWhnLmNsb3VkZnJvbnQubmV0L3VzZXJmaWxlcy8xMTEyOC8xNDIwNS9ja2ZpbmRlci9pbWFnZXMvMig2MikucG5nIiwiQ29uZGl0aW9uIjp7IkRhdGVMZXNzVGhhbiI6eyJBV1M6RXBvY2hUaW1lIjoxNzY1ODMzNjkyfX19XX0_&Signature=FDtHkm3S2p6wmppQODOpwTbiEqLrhd8EHIQvqmmNWx4JBrLDvr0oznoOkUh2bncXjwM0qOsC7ksPr1fLV4QRa0ZWnCXrbDmZvGSlwOQ9MdZp~J8mFHykgEA~SzHMi02PsXC4oO0DDtSSFltQo5v1YU8TwCumJNi7sro4An9rUXjjh4xcH3hXpWXR1GpdKXxedtd2kqecBNn~63FPxuH1LkyWV36NY3cHH8-QROo8QGZIH4YFYqcyd6LuUT9uCumjnXK-PSs9SEUBW85JofT7bBzHjnguu52PME25ImeB2Vysy7HYQUerXiM73-ODYhzCuJ1sTsPMsYaYF9DxGwal7Q__&Key-Pair-Id=K2TK3EG287XSFC)
4. Copy the HTML from the right side after the HTML has been cleaned
.png?Policy=eyJTdGF0ZW1lbnQiOlt7IlJlc291cmNlIjoiaHR0cHM6Ly9kemY4dnF2MjRlcWhnLmNsb3VkZnJvbnQubmV0L3VzZXJmaWxlcy8xMTEyOC8xNDIwNS9ja2ZpbmRlci9pbWFnZXMvMygzMykucG5nIiwiQ29uZGl0aW9uIjp7IkRhdGVMZXNzVGhhbiI6eyJBV1M6RXBvY2hUaW1lIjoxNzY1ODMzNjkyfX19XX0_&Signature=OiV6XsV9269Sqb4ffON9dzh12yPlRTsF8UAON3sEQUFYZqJrLisAxra4D~l3wTTuNH1RX-uYDeyreExsl6J2zkvjJ2HOXy9iYznayHY07p7dWqtpcYu6gyGUCW2iGEq3YmL16pHISg6h1uU2-PfKx1LWa0HLoq2B3xoLuIAznmQFsr5fc~MZ7Xttu6tg2vVQQLZ0ODUh78ZXzAenZ~SaTAYPR-FpeXJgnDbQWFiy1sjoOuBD~3jsnasUYexNzqiGBmW9HWXr5lK6ldnT4YGrn5ln-t0aiflJPit9CCYw-CWm4htLLo9ujtoFs7nnalpzdhQjGauQ5GhMLdcXojVhGA__&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=eyJTdGF0ZW1lbnQiOlt7IlJlc291cmNlIjoiaHR0cHM6Ly9kemY4dnF2MjRlcWhnLmNsb3VkZnJvbnQubmV0L3VzZXJmaWxlcy8xMTEyOC8xNDIwNS9ja2ZpbmRlci9pbWFnZXMvNCgxMSkucG5nIiwiQ29uZGl0aW9uIjp7IkRhdGVMZXNzVGhhbiI6eyJBV1M6RXBvY2hUaW1lIjoxNzY1ODMzNjkyfX19XX0_&Signature=BWO~Ij3KiYQ0Xw7AEMrR6q0JXKbcXifb71ceAeCl2PpzXxekimcN4P1j~~s3ielEXb53LKRkA72YPXYuTHXyOA9SI8Gm2GX-E~OmHuWvzyTr0dROS0Fob6GONg2DBZua38U-bKiO8QNcuCRFfx4RFT6aRPv6XxQ5WLPokHHfgSI1076k5zUKymIGV~mjXePkU4TVsuSTu~KTudoOmRdfQrcKsBEWGyCP71uvajOadzp6wauqYSoZn1uKmT4RG6N88uhQ2aIaSmSvWaNZWqc9cXAiInuK7UTNrXK8TU5~zh7kxocjeD65ixMDGkRloRMvHlGKnBteX2CFsF8lJ7rX2g__&Key-Pair-Id=K2TK3EG287XSFC)