your options include using a thermowell or thermo pocket to insert the probe into the flow if the liquor, or employ a compression fitting or gland type fitting to insert the naked probe into the flow and seal it.
if using brass plumbing compression fittings or SS swaglock type compression fittings to seal against your probe dont use the supplied olive or ferrules as these will become crimped onto your probe permenantly, instead substitute the olive/ferrules with orings with a similer id to the od of your probe with at least a 1mm thuckness, you can always use 2x or 3x
a cheap diy thermowell can be made from soldering a flat bit of copper to the end of some micro bore tubing 8mm od tube with a 1mm wall will have a 6mm id
cut off a short bit of tube, split it with tin snips or a hacksaw, and use a vice to open and flatten it, use flux and sit the flat plate atop a length of tube heat till the flux smokes and dab with solder and when hot enough it will seal on the cap, you can tinsnip/file the surplus flat copper off - done .. just use zero lead solder and wash off the toxic flux thouroughly.
probes tend to contain the actual sensor at the tip, so if using a thermowell good positive contact with the themowell end cap is way more crucial than a snug fit in the tube diameter, ideally both is best but ..:)
here is one i made from 15 and 10mm copper tube and can accommodate more than one thin probe at a time
and in use
edit ** i had this link saved for a good reason
https://www.aliexpress.com/item/USA...lgo_pvid=7e68eced-9910-4dfb-a8d4-fad3ff46c892
