Official portal notes e-Visas are not extendable and not convertible; fees shown on site.
The official eVisaPH portal states: issued Philippine e‑Visas are not valid for conversion to other visa types and are not valid for extension of the authorised period of stay.
Fees are specified on the official website and are subject to change. Confirm your fee on evisa.gov.ph before paying.
Visa fees (reference)
Fees vary by mission and may change. Reference fee schedule (official): Philippine Embassy Moscow. eVisaPH fees are shown on: eVisaPH fees terms.
eVisaPH states issued Philippine e-Visas are not valid for extension of the authorised period of stay.
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