BTMS-50 is a conditioning self-emulsifier. if you can't readily find it in your country or it's too expensive, here are some alternatives you can try.
Conditioning Emulsifier - Getting Started with BTMS
33rd PARALLEL, BTMS 50 Conditioning Emulsifier, Sizes 2 OZ to 1 LBS, 100% Natural Plant Derived, Behentrimonium Methosulfate Cetearyl Alcohol Emulsifying Conditioner
My adventures with Olivem 1000 emulsifier - curlytea
ORGANIC NATURE: Our BTMS 50 Conditioning Emulsifier is a highly effective conditioning compound, BTMS derived from the natural plant oil (Rapeseed
9.6 oz BTMS 50 Conditioning Emulsifier for Making Leave-in Conditioner, Premium BTMS 50 Conditioning Emulsifier Granules, Higher Activity than BTMS
Polyglyceryl Oleate - Water-in-oil emulsifier
Sorbitan Oleate Substitute Selection
A Few Important Ratios for DIY mixes - curlytea
4 OZ BTMS 50 conditioning emulsifier derived from colza oil and Consists of Behentrimonium Methosulfate, Cetyl Alcohol and Butylene Glycol. BTMS 50 emulsifying wax for Beauty Products 4 OZ : Beauty & Personal Care
Working with Mucilage-rich Irish Moss - curlytea