Should I declare my 1 year and 6 months work experience even if I don't have a COE to back it up?

Hello po. I need some advice and insights po about my situation.

I was previously employed for 1 year and 6 months sa isang small firm. Reason ko po sa pagresign is walang govt benefits. Nagpromise sila sa'kin na after 6 months meron na pero hanggang sa umabot na ng taon, voluntary pa rin akong naghuhulog sa mga govt benefits.Wala rin bayad OT kahit 2-3 hrs na kaming OT.

Lately ko lang nalaman na ang pinagworkan ko is di sila registered sa SSS, Philhealth at PagIBIG. Naburn out ako sa work kaya I decided to resign. Ang problema po is hindi sila nagpo-provide ng COE. Di na sila nagrereply sa text/tawag at email.

Should I declare my 1 year and 6 months work experience even if I don't have a COE to back it up? Maco-consider bang red flag sa recruiter if walang COE na mapro-provide? Ano po ba tamang approach kapag interview regarding on this?