Brave wallet error "The method 'wallet_addEthereumChain' does not exist / is not available."

[florianajir]

Description

Unable to add custom RPC to brave wallet using the default metamask api call

Steps to Reproduce

1. Go to https://chainlist.org/
2. Search for any network (e.g. Fantom)
3. Click on "Add to metamask" button

Actual result:

Console error log (RPC Error)

Expected result:

Should open a wallet popup to review the network requested to add

Reproduces how often:

Always

Brave version (brave://version info)

Brave | 1.29.76 Chromium: 93.0.4577.58 (Build officiel) (64 bits)
Revision | c4410ece044414ea42fa4ba328d08195e818a99c-refs/branch-heads/4577@{#1076}
OS | Windows 10 OS Version 2009 (Build 19043.1165)

Version/Channel Information:

• Can you reproduce this issue with the current release? yes
• Can you reproduce this issue with the beta channel? yes
• Can you reproduce this issue with the nightly channel? yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? no
• Does the issue resolve itself when disabling Brave Rewards? no
• Is the issue reproducible on the latest version of Chrome? no

Miscellaneous Information:

I read somewhere that brave wallet share the same codebase as metamask but now seems not, have you any metamask fork version upgrade guidance to clarify how often you pull changes from base ?