Assuming you mean the jailhouse call?
The soundcloud of that conversation no longer seems to be available.
Iirc, it was a conversation where KM was complaining that the kids were driving her crazy, she spoke about her daughter wearing a green dress and it seemed to me that she/they were unusually concerned about what will happen (of all things!) to the living room set. SG said not to worry, family will help her with that. At the time i speculated that
maybe there was something extra special about the furniture and the green dress.
She attempted to give him a phone number in code, ie.a school fee, but SG did not get it right away.
imo, speculation.
ETA
Here's What to Expect From the Dan Markel Murder Trial
September 23, 2019
"Several days after his May 2016 arrest for the murder of Dan Markel, Sigfredo Garcia made a jailhouse phone call to Kathy Magbanua, his former girlfriend and the mother of two of his children. He told her he would "be out soon and [would] either file a lawsuit or 'get the hell out of Dodge' and leave everything behind them," according to an FBI transcript of the call."
"Also expected to testify is Jessica Rodriguez, the mother of one of Rivera's children. Shortly after Garcia's arrest, she texted Magbanua in an angry frenzy, according to a transcript of an FBI wiretap of Magbanua's phone.
"The reason your husband is in jail becouse of you n charlie," Rodriguez texted. "Like everyone doesnt know that [sic]."
rbbm.