Button to check a box and then redirect to generate an Exact Forms doc

I need help to accomplish the redirect to the Exact Forms doc generation. Here is what I tried but not correct:

URLRoot() & "db/" & Dbid() & "?a=API_EditRecord" &
    "&rid=" & [Record ID#] &
    "&apptoken=cav92prc9it7rfdfbvc32xuy2vj" &
    "&_fid_172=1" &
    "&rdr=&URLencode("https://www.aws-juiced-client2.com/Juiced/ExactFormsPlus10/doc_merge_ua.aspx?"
& "request="
& Base64Encode("clientid=Q2683"
& "&appid=" & AppID()
& "&tpdbid=" & [_DBID_DOCUMENT_TEMPLATES]
& "&tpid=2"
& "&fn=BoM Purchase Order"
& "&msid=" & URLEncode ([Record ID#])
& "&msdb=" & Dbid()
& "&faid=58&efpdte=59"
& "&docfmt=doc&stream=y"
& "&apptoken="))