@Rushi84  what kind of form is it

@srujan1981 are you able to share the template package over a drive?

@CØK is this happening in designer preview?

@PrasadGo in your settings.xml which repo is being referred?

@fulongt37334138  what kind of form is it? 1. PDF Then you need to write a script on exit to validate if two are selected or not2. Same logic as 1 in case of adaptive form on value commit and validate

@Vinit_Pillai is it TTF?

@klothoskir1  the value will be in rawValue can be get using fieldname.rawValue myField1.rawValue + myField2.rawValue + myField3.rawValue var is supported so you can put it in var

@sesmic you can create custom checkbox if you need RTE in the text, OOTB this isn't possible.

@chayanika_27 lets try to just start with one file and see if the file has any policy or protection. Reason can be any thing at doc level preventing the merge operation. DDX looks fine though. 

@StrawHatM23 yes, you need to use sharepoint rest API to connect to AEM forms during the submission via a custom servlet. Doable easily.    https://learn.microsoft.com/en-us/sharepoint/dev/sp-add-ins/complete-basic-operations-using-sharepoint-rest-endpoints