已知函数$f\left(x\right)=\sin \left(2x+\frac{\pi }{3}\right)$，若存在$a\in \left(0,\pi \right)$，使得$f\left(x+2a\right)=f\left(x\right)$恒成立，则a的值是（   ）

根据短文理解选择正确答案。

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