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A high statistics data sample of the $K^{+}$ decays is recorded by the OKAcollaboration. A missing mass analysis is performed to search for a lightinvisible pseudoscalar axion-like particle (ALP) $a$ in the decay $K^{+} \to\pi^{+} \pi^{0} a$. No signal is observed, the upper limits for the branchingratio of the decay are calculated. The $90\%$ confidence level upper limit ischanging from $2.5\cdot10^{-6}$ to $2\cdot10^{-7}$ for the ALP mass from 0 to200 MeV/$c^{2}$, except for the region of $\pi^{0}$ mass, where the upper limitis $4.4\cdot10^{-6}$.

Searches for the light invisible axion-like particle in $K^{+}\to\pi^{+}\pi^{0}a$ decay