dynamic.dialup.gvt.net.br has no TXT records.
Question and response
Question
dig dynamic.dialup.gvt.net.br. TXT
Answer
The response has no answer records.
Authority
dynamic.dialup.gvt.net.br. 86400 SOA dns1.gvt.net.br. operacao.gvt.net.br. 9 28800 14400 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0