How 꽃차례 is pronounced? Kkot-charye or kkoch-charye? For example, 있다 is pronounced "itta", but 있습니다 isn't pronounced "itseumnida".
According to Naver dictionary it is pronounced as 꼳차례
꽃-차례 -次例 Pronunciation [ 꼳차례 ]
있습니다 is not pronounced itseumnida because ㅆ 받침 followed by ㅅ is always pronounced as ㅆ.
꽃차례 is pronounced as 꼳차례 /k͈o̞t̚t͡ɕʰa̠ɾje̞/. Some pronounce it incorrectly as 꼳차레 /k͈o̞t̚t͡ɕʰa̠ɾe̞/ as it is quite difficult to pronounce 례.
Note 1: You should avoid romanizations because they do not reflect 경음화 (fortification) at all. For example, the romanization of 국가 is gukga but the pronunciation of 국가 is 국까 /kuk̚k͈a̠/.
Note 2: 있다 is pronounced as 읻따 /it̚t͈a̠/ (Some pronounce it incorrectly (for convenience) as 이따 /it͈a̠/); 있습니다 as 읻씀니다 /it̚s͈ɯmnida̠/ (Some pronounce it incorrectly (for convenience) as 이씀니다 /is͈ɯmnida̠/).