Hi Abinash - thank you for reaching out and bringing this to our attention.
You're right, the standard Dutch mobile number format is +31 6XXXXXXXX, which totals 11 digits including the country code and our form currently requires a 12 digits which is causing the issue you're experiencing.
While we work on a fix could you try this workaround: Add a leading zero after the country code, e.g., +31 06XXXXXXXX. While this isn't standard formatting, it may satisfy the digit requirement temporarily.
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Victoria Scott
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