We calculate the form factors for the kaon semileptonic decay process
using the PACS10 configurations, whose physical volume is more than
(10 fm)$^4$ very close to the physical point. The configurations
were generated with the Iwasaki gauge action and $N_f=2+1$ stout-smeared
nonperturbatively $O(a)$-improved Wilson quark action at the three lattice
spacings, 0.085, 0.063, and 0.041 fm. We present updated results for the form
factors, and discuss their continuum extrapolations, momentum transfer
interpolation, and short chiral extrapolation to tune the simulated
pion and kaon masses to the physical ones. From the results with various
analyses, the systematic error of the form factor at the zero momentum
transfer is estimated. The value of $|V_{us}|$ is
determined using our result, and is compared with those using the previous
calculations and also those determined through the kaon leptonic decay
process.